Anxiety Manual

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Introduction: What is Anxiety?

Anxiety, in its simplest terms, a response to perceived threat. This response contains different components including changes to thoughts, bodily reactions and behavioural responses. Anxiety is experienced by all living animals and is a normal and useful part of their mental activity. Throughout all of human history anxiety has been useful- if our early ancestors did not fear dangerous predators, they would not have survived.

Feeling fear in response to genuine threats is an essential part of human experience- fear motivates us to avoid or escape from threat and prepares your body for action. However, fear becomes a problem when it is experienced excessively, recurrently or in a way that is disproportionate to the true level of danger you are in. These “false alarms” in our response to danger, or clinical anxiety as they would be officially termed, can become highly distressing and debilitating to those who experience them.

Clinical anxiety has many forms including generalized anxiety disorder, panic disorder, agoraphobia, social anxiety disorder, specific phobia, obsessive-compulsive disorder (OCD), body dysmorphic disorder, posttraumatic stress disorder, and illness anxiety disorder. Anxiety disorders such as these are the most common form of mental health disorder in the world today. (Kessler, Chiu, Demler, & Walters, 2005)

Treatment of anxiety disorders has historically been undertaken using a disorder focused approach (Deacon, 2013) in which conditions are diagnosed using a list of symptoms in a standard classification manual such as the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V) and the International Classification of Diseases, 11th edition (ICD 11). Research is focused on how these disorders form and maintain themselves and on developing more effective treatments. Treatment usually proceeds systematically- clinicians assess a patient’s symptoms, and then develop a treatment plan to alleviate each symptom and disorder in turn.

Anxiety disorders may have very different symptoms and may lead to experiencing anxiety in response to very different triggers, but the essential building blocks that form and maintain these disorders are remarkably similar. Mental processes such as the overestimation of threat, and patterns of acting in response to this threat are often very similar across different conditions.

Anxiety disorders should not be considered “defects”. Rather, they exist on the same continuum as normal, healthy anxiety, and are made up of the same biases in thinking and patterns of acting that can be observed in people who are not diagnosed with any kind of disorder. It is only the frequency, intensity or duration of these individual factors which varies from diagnosed to non-diagnosed individuals.

Relying fully on diagnosis using classification tools can be unhelpful in treating anxiety. Many people who experience severe, life-impacting anxiety do not meet the criteria for any diagnosis. Furthermore, an individual may be experiencing a very specific set of anxiety symptoms and yet meet the criteria for multiple different disorders. Due to the closely related nature of many anxiety disorders, pinning down a single “correct” diagnosis can be tricky. For example, imagine a woman with recurring, debilitating fears that she has contracted colon cancer, who continually monitors her body for the signs and symptoms of this illness, and who experiences panic attacks whenever she thinks she has spotted a sign. Should she be diagnosed with obsessive compulsive disorder, illness anxiety disorder, or panic disorder? Or consider a man who experiences crippling anxiety in large crowds and is terrified that he will have a panic attack in a public place as this will cause him to lose control and make a fool of himself. Would a clinician diagnose this man with panic disorder, agoraphobia, or social anxiety, or some combination of all three?

Chapter 1: Overestimation of Threat

Jenny is an administrator in a law firm with an intense fear of public speaking. Her work does not often require her to speak in front of large groups, but every few weeks her boss asks her to present reports and updates at meetings, which requires her to report on complex, technical issues in front of a large room of work colleagues. While her colleagues and superiors often report that Jenny handles these presentations well, she herself experiences intense dread in the run up to each one. She frequently anticipates making a fool of herself in front of all the people she works with, and her mind is constantly filled with worst-case scenario predictions such as “I’ll mis-pronounce a client’s name and everyone will laugh” or “I’ll be sweating and shaking so much that everyone will notice and it’ll be so embarrassing.”

Before each presentation Jenny became convinced that if she made any errors she would be fired on the spot and her career would be over. To combat these fears, Jenny prepared excessively for each presentation, staying up for hours and hours the night before until she had each figure checked and every sentence memorised word for word. She would also put on dark clothing and wear makeup to make sure any sweating or blushing wouldn’t be noticeable to her colleagues.

Fear of public speaking, like that which Jenny experiences, is very common. A key component of this anxiety is overestimating the threat that public speaking represents. In Jenny’s case, she has been proven on multiple occasions to be a competent public speaker, and her fears about losing her job and making a fool of herself are clearly unreasonable. And yet the fear persists.

Overestimation of threat is a common component of many anxiety disorders. There are two main types of threat overestimation: overestimating the severity or cost of the feared events (e.g. “if I mess up this presentation I’ll lose my job”) and overestimating the likelihood of the feared event (e.g. “I’m going to get the figures wrong if I don’t practice all night”).

Likelihood overestimation occurs when the feared outcomes are judged to be much more likely than they really are. Fear of flying is a common example- the odds of a plane crashing are extremely low and yet people with this phobia will often avoid flying altogether due to the fear of a crash.

Severity overestimation, also called catastrophising, occurs when the feared outcome is seen as far more unbearable than most people would consider reasonable. Examples may include believing that a bee sting would be unbearably painful and dangerous, or believing that performing poorly in an exam will “ruin your career prospects forever”.

A Model of Threat Overestimation

A cognitive-behavioural model can help us understand threat overestimation and its role in anxiety. Cognitive Behavioural theory states that thoughts play a key role in the experience of emotions. In this view emotions are not caused directly by situations or events around us, but by our interpretation of them (Beck, 1976). Particular interpretations will often lead to specific emotions, for example interpretation of events based around loss will produce feelings of sadness, while interpreting events as a direct attack on you personally may lead to feelings of anger. Similarly, interpreting a situation or stimulus as dangerous in a way that exaggerates or overestimates the level of threat present will naturally lead to feelings of anxiety. (e.g., Amir, Foa, & Coles, 1998; Beck, Emery, & Greenberg, 2005).

Think back to Jenny’s case. The presentations she gives are not threatening or dangerous in and of themselves. Rather, it is her interpretation of her situation and the possible consequences that leads to her distress. By overestimating both the likelihood of something going wrong, and the severity of the consequences, Jenny is inadvertently turning a harmless situation into a tremendous source of worry.

Since it is the interpretation and not the situation itself that is the real issue, challenging and correcting the overestimation of threat is often a key part of overcoming any anxiety disorder. Often this process occurs naturally- people overestimate the threat a situation poses, and then experience proves them wrong. But for others, especially those diagnosed with clinical anxiety, this self-correction does not occur. Jenny has given many presentations and received positive feedback on each occasion- why hasn’t she come to the conclusion that she is a good public speaker? Why does she still view these routine presentations as such a threat in the face of such contrary evidence?

Safety Behaviours

One reason threat overestimation persists in the face of contrary evidence is the presence of safety behaviours- actions taken in order to detect or avoid the feared situation. Safety behaviours are undertaken in order to reduce anxiety but often they serve to maintain it by leading individuals to think that they are dependent on them to avoid feeling anxious (Salkovskis, 1991).

Jenny’s response to feeling nervous the night before giving a presentation was to rehearse over and over for hours. When she performs well in her presentations, she concludes that it must be because she spent so long rehearsing. Rather than seeing that she is actually a competent public speaker and that her regular presentations pose no threat, her over preparation serves to cement the fear in her mind. As long as she continues to perform the safety behaviour of excessive rehearsal, Jenny never gets to see that she can function fine without it, and her overestimation of the threat posed by public speaking remains unchallenged (e.g., Salkovskis, Clark, Hackmann, Wells, & Gelder, 1999).

Information Processing Bias

When feeling fear, all humans have a tendency to filter the information around them in a way that confirms their threat overestimation. This bias, like other aspects of fear, has useful origins in normal human behaviour. When danger is present, being vigilant for any potential source of harm is an essential part of survival. But when we are not in any danger, being predisposed to see threats can keep us overestimating the danger we are in.

Once specific way our brains inadvertently keep us overestimating the threat of non-dangerous situations is through a process called selective attention. This effect simply means that whenever we perceive a potential threat in our surroundings, our attention automatically shifts to fully focus on the source of danger. This, as you can probably imagine, is a very useful trait when confronted with genuine sources of danger- fully focusing on the threat and disregarding all else can give a huge survival advantage. But this effect can also serve to provide “evidence” that a situation is dangerous when in fact it is not.

Going back to Jenny’s fear of presentations, her belief that standing up in front of a large group is a threatening and dangerous situation causes her mind to focus in on any possible source of “danger” around her. As such she instantly picks up on every whisper or disapproving look in the crowd and interprets them as being a sign that she has made an error and people are talking about her. This only serves to reinforce her notion of public speaking being an unsafe situation. Someone who did not hold this fear may well not pick up on the whispering from the crowd, and so continue to have no reason to feel under threat.

A similar mechanism known as confirmation bias also comes into play in keeping threat overestimation firmly in place. When it comes to survival, it is often better to assume you are under threat and be proven wrong that to assume safety and be caught out. As such, when we think we may be in danger, out brains automatically seek out information to confirm our suspicions. If our perceptions of danger are inaccurate or overestimated, as they are in clinical anxiety, our brains will still collect information to support the sense of danger, drawing on whatever they can find to confirm our fears. This leads to the interpretation of perfectly harmless events and stimuli as being evidence of danger, and at the same time causes us to disregard any evidence to the contrary.

For example, as Jenny looks around the room while giving her presentation, she may interpret the faces of her colleagues as being critical or disapproving when a more objective viewer may see them as being neutral. She would also be more likely to disregard or explain away any positive or encouraging faces she sees in the crowd, perhaps thinking they are smiling out of pity. Since our brains are wired to assume threat rather than assuming safety, once we feel under threat all evidence tends to point in the same direction.

Ours minds do not just draw attention to threats and make us predisposed to interpret ambiguous information as being threatening- they can also affect how we recall information. Memory bias causes us to recall fear-related information more easily than non-frightening memories. Memory bias serves to maintain our threat overestimation by ensuring that any distressing memories relating to our object of fear stay fresh in our minds. Jenny may be unable to recall in great detail the many occasions she handled public speaking well, but the one occasion she feels that she made a mistake will be firmly lodged in her memory.

A final bias that contributes to threat overestimation is known as emotional reasoning. The very experience of feeling afraid can give rise to an increased sense of danger- we notice that we are feeling afraid, conclude that there must be a reason, and so interpret our situation as being threatening (Arntz, Rauner,& van den Hout, 1995). This can form a vicious cycle in which a situation produces feelings of anxiety, and these feelings contribute to higher interpretation of the threat level, leading to further anxiety.

Identifying Threat Overestimation

You can ask yourself the following questions to identify whether threat overestimation is at play when feeling anxious:

  • What goes through your mind when you’re feeling anxious?
  • What, specifically, do you think will happen in this situation?
  • What is it that motivates you to avoid this situation?
  • What do you think is the worst thing that could happen to you in this situation?

Common Examples of Threat Overestimation

Here are some common examples of threat overestimations relating to different kinds of feared situations and stimuli.

Likelihood Overestimation Severity Overestimation
If I go near a snake it will definitely bite me If I get bit I could die
The bee will definitely sting me The pain from a sting would be unbearable
Negative Self-evaluation
Everyone will think I’m awkward and boring No one will ever want to be friends with me
Everyone will notice my spots I’ll never find anyone who wants to marry me because I’m so ugly
Eating food on the “best before” date will cause me to get sick Getting sick will mean I have to go to hospital
Using a public toilet is unsafe and could cause me to get infected I could get HIV from a toilet and die
Social Contact
If I’m ever alone with a man he might assault me If I’m assaulted I could be killed
If my son hasn’t texted me it means his plane crashed My son could be dying or dead right now

Implications for Different Fears

Natural Environment and Disasters

Threat overestimation plays a part in fear of many potentially catastrophic situations such as being in a car crash, standing on a high ledge, being in a confined space, flying, and being in a storm. Clearly the consequences of crashing your car, or falling from a high place, or being in a severe lightning storm would be disastrous, but all of these things are extremely unlikely. Likelihood overestimation is clearly playing a part here, leading one to believe these occurrences are likely (or even certain) to happen despite the low objective risk. Severity overestimation can also be a factor, for example in causing you to believe that if lighting hits your house it will catch fire and lead to a fatal explosion.

Many people who fear these situations can also come to fear experiencing symptoms of anxiety while in them. A man who is highly anxious about car crashed may believe that if he becomes very anxious his hands may start to shake on the steering wheel, causing him to lose control of the car. Equally, someone who is afraid of being in enclosed spaces such as elevators may interpret their anxiety-related shortness of breath as a sign that they are running out of air and likely to suffocate (e.g., Radomsky, Rachman, Thordarson, McIsaac, & Teachman, 2001). Severity overestimation can also focus on the imagined embarrassment that would occur as a result of feeling anxious- for example panicking in public and making a fool of yourself.

Negative Evaluation

Threat overestimation plays a key part in fear of social situations, as we saw with the example of Jenny. Overestimations often concern the probably and significance of being observed, judged or criticised by others or being seen as foolish. People with this fear overestimate the likelihood that onlookers will notice their shortcomings, while also overestimating the severity of such observance- believing that appearing foolish to others would be catastrophic to the same extent as severe injury or death.

These kinds of threat overestimations of threat lead people to avoid social situations and go to great lengths toa void being noticed or seen as foolish. Avoiding feared social situations serves to keep the threat overestimation in place, since doing so prevents you from seeing that other people are far less observant of your shortcomings than you might think.

Fear of the Importance of Meaning of Thoughts

Everyone experiences unwanted thoughts from time to time. However, some people come to fear the significance of these thoughts and begin to view them as a threat. Obsessions, a central aspect of obsessive compulsive disorder (OCD), are overestimations of the cost of experiencing unwanted thoughts on topics such as contamination, sex, violence or physical safety. People with OCD often misinterpret these intrusive thoughts as having some significant and disastrous meaning to them personally. They may worry that they will inadvertently act on intrusive violent or sexual thoughts or may fear that their thoughts indicate that deep down they are bad people.

People who regularly experience distressing intrusive thoughts may take steps to try and avoid them, such as staying clear of situations that trigger such thoughts, or performing mental rituals to “counter” the unwanted thoughts with more acceptable ones. As with all safety behaviours, these rituals and avoidance strategies prevent people from seeing that intrusive thoughts are, in fact, totally harmless.

Fear of Somatic Cues

Fears regarding changes and sensations within your own body are common in many anxiety disorders. These fears of somatic cues come in three main types: fears around immediate versus long-term health issues, fears regarding anxiety or arousal related sensations, and fears that internal sensations will cause external negative outcomes. These fears of internal somatic cues are often experienced across different anxiety disorders- any they may also be experienced by individuals who do not meet the criteria for any specific disorder. It’s therefore important to think about the similarities between the symptoms present in different disorders and take a trans-diagnostic­ approach when thinking about somatic cues.

One common form of fear around somatic cues is the belief that harmless internal sensations will lead to some form of negative outcome. Individuals with panic disorder may interpret a raised heartbeat as a warning sign of an imminent panic attack, someone with social anxiety may fear trembling or blushing due to the possibility of them being noticed by others, and someone with illness anxiety may interpret harmless muscle tension or a mild headache as something far more serious. Individuals who fear somatic cues spend a lot of time monitoring their bodies for these “warning signs” and become hyper-sensitive to any changes in their body.

Fear of Contamination

Fear of being contaminated is a key feature of both OCD and illness anxiety disorder. Individuals with this fear are often anxious about situations or stimuli they perceive to be unclean, such as public restrooms, people who are sick, or hospitals. While fears around physical contamination are the most common example, fears of mental contamination are also possible; some people may fear “unclean” thoughts of a sexual, immoral or unclean nature (Rachman, 2006).

Fears around contamination often lead individuals to avoid any sources of contamination and to engage in frequent cleaning, hand washing and similar activities. These excessive cleaning and cleansing activities prevent people with contamination fears from ever seeing that their feared situations or stimuli pose no real threat. Someone who washes their hands dozens of times per day, for example, never gets to see that not doing so has no negative outcome, and so their fears remain unchallenged.

Fear of Traumatic Events (and Post Traumatic Sequelae)

Most people who witness or experience traumatic events first-hand recover and suffer no long-term psychological consequences. However, some who experiences traumas such as severe accidents, disasters, sexual assaults and other criminal events develop symptoms of post-traumatic stress disorder (PTSD) in the wake of these events (e.g., Rothbaum, Foa, Riggs, Murdock, & Walsh, 1992). Symptoms such as nightmares, flashbacks and feeling constantly on edge are common after any traumatic event, and in most people they subside naturally. In those with PTSD, these symptoms remain and can cause significant psychological distress.

PTSD symptoms are grouped into four main categories: intrusion, avoidance, negative changes to thoughts and mood, and alternations to mental arousal and reactivity. A common trait among trauma survivors is that they tend to hold unrealistic beliefs about the danger of the world, or other people, or even themselves (Foa, Ehlers, Clark, Tolin, & Orsillo, 1999). Threat overestimation beliefs such as “the world is a dangerous place” or “people cannot be trusted” are common.

One common threat overestimation is a fear of being re-traumatised. Individuals who have been through traumatic events may now view the world as being unsafe, and so fear having the same experience again. They may start to feel especially vulnerable in situations similar to their traumatic experience. This could be seen as an overestimation of the likelihood of the traumatic events reoccurring- just because a person was assaulted or involved in a crash once, there is no reason it is likely to occur again. Overestimation of the severity of being re-traumatised are also a common factor- individuals may believe that if something happened to them again, they would never be able to recover.

Another possible form of threat overestimation is fear surrounding the interpretations of trauma symptoms. Individuals may believe that the symptoms themselves pose them some form of threat, such as fearing that nightmares and high anxiety levels are a sign hey are losing their mind. These fears about experiencing trauma symptoms often cause individuals to avoid any situations similar to their original trauma, and may incline them to engage in unhelpful coping strategies such as self-medication with alcohol or drugs. Both avoidance and unhelpful coping only serve to exacerbate the individual’s distress by reinforcing the notion that their symptoms are harmful.

Chapter 2: Safety Behaviours

As mentioned in chapter 1, safety behaviours are actions an anxious person takes in order to reduce the anxiety they feel. On the surface this seems like a normal and useful way to act. However, safety behaviours reinforce the link between the stimulus/situation and a need to escape or avoid, thereby keeping exaggerated perceptions of danger or threat in place. For many people, experiencing their feared stimulus directly, without any safety behaviours, would be enough to convince them that it is not as dangerous as they had believed. So long as they continue to rely on safety behaviours this is not possible. Safety behaviours are sometimes referred to as unnecessary protective behaviours, since they are aimed at providing some kind of protection against a perceived threat that offers no real danger.

Recent research into safety behaviours has looked into the role they play in developing and exacerbating symptoms of fear, and the effect they have on attempts to reduce anxiety through exposure to the feared stimulus.

Safety behaviours are normally linked to the type of threat a person anticipates. A patient with anxiety around having a heart attack may repeatedly monitor their pulse or heart rate to try and reassure themselves and avoid any activities that raise their heart rate (Salkovskis, 1991). A person who fears spiders may feel the need to scan the floor for any movement before entering a room, and so on. See the table below for examples of safety behaviours relating to different anxiety disorders.

Disorder Perceived Threat Safety Behaviour
Panic Disorder Fear of cardiac arrest during a panic attack Stop drinking caffeine as it raises heart rate
Agoraphobia Fear of making a fool of oneself when panicking in public Avoid crowded places
Only leave the house with a trusted companion
Social anxiety disorder Fear that others at a social gathering will notice your discomfort and anxiety Wearing dark clothes so that no sweat patches are visible
Mentally replaying conversations in case you said something embarrassing
Generalised anxiety disorder Fear that you will get fired Frequently asking your boss for reassurance about your position
Researching other jobs just in case
Phobia (dogs) Fear of unprovoked attack from vicious dogs Avoiding streets with dogs in the gardens
Obsessive compulsive disorder Fear of becoming contaminated and seriously ill when going to public places Opening doors with a paper towel over your hand
Frequently cleaning your hands with sanitizer
Posttraumatic stress disorder Fear of being attacked in public places Never leaving the house alone
Carrying pepper spray in case of an attack
Illness anxiety disorder Fear of being diagnosed with skin cancer Extensively researching signs and symptoms
Checking moles for any changes daily

Different Kinds of Safety Behaviour

The two main forms of safety behaviour seen in people with anxiety disorders are preventative and restorative safety behaviours. Preventative safety behaviours are those which aim to reduce the threat of the feared situation- examples include checking a room for spiders or not directly touching the handle when opening a door. Restorative safety behaviours are aimed at bringing the situation back to a desired state after contact with the threat- examples include washing hands after contact with the door.

Awareness of safety behaviours differs greatly between different people with anxiety. Some may be aware of the actions they are taking, and why, while for others the action may be so automatic that they do not realise they are performing the action to keep themselves safe.

Misattribution of Safety

The primary reason safety behaviours are problematic is that the anxious person believes their safety to a result of the safety behaviour- rather than the fact that the situation is not dangerous (Salkovskis 1991). Rather than being able to see that flying, or contamination, or whatever the feared situation is poses no real threat, the anxious individual misattributes their safety to the actions they have taken and continues to think that the situation would have been dangerous had they not acted in this way.

As an example, imagine a man who fears having a heart attack if he ever starts panicking in public. His safety behaviour is to find a public bench somewhere quiet and sit until he has calmed down every time he feels his heart rate increase. After a few minutes of sitting he starts to calm down and thinks “thank goodness I took the time to sit down- I could have had a heart attack and died otherwise!” This is totally inaccurate- it’s not possible to have a heart attack as a result of panicking- but this man firmly believes that his actions are the only reason he is safe.

Chapter 3: Intolerance of Uncertainty

Ever since he watched a documentary about healthy eating and organic farming in school, Simon became increasingly worried about getting ill from eating food contaminated with chemicals and pesticides. As he grew older he became very preoccupied with the idea of getting a serious illness as a result of exposure to deadly chemicals from his food. He began to cut all nonorganic food from his diet and went to great lengths to make sure his fruit and veg came from farms that didn’t use any pesticides or chemicals. He stopped eating at restaurants which couldn’t prove where their food had come from, and even food made by his fiancé was subject to close scrutiny before being eaten.

Despite all his precautions, Simon still feared he would somehow get ill. Every time he thought he felt any symptoms of illness he would check them online to see if they were sings of something serious, and went to the doctor regularly to get himself checked. And yet even with his obsessive checking of his food and health, Simon felt he could never truly be sure he wasn’t getting seriously ill, and so was constantly worried and distressed by the possibility.

Simon’s fears and hardships stem from his inability to tolerate uncertainty. To him, not being able to know with certainty what state of health he is in is unacceptable and causes him great discomfort. This discomfort causes him to go to ever greater lengths to assess his health and ensure his diet is risk-free on a doomed quest to eliminate any uncertainty from his mind.

All of life involves some level of risk and uncertainty. Each time we switch on an oven or get in a car, we have to accept some small level of risk. For most people, this is something they simply acknowledge and accept- the risk level is small and unavoidable. By contrast, individuals such as Simon display a trait known as intolerance of uncertainty (IU), a trait common to people experiencing many forms of anxiety disorder. People with high IU find any level of risk or unpredictability intolerable and believe it is necessary to have absolute guarantees of their safety before they feel safe. Where most people are happy to be “pretty sure”, people with IU have to be 100% sure before they feel safe.

IU can be split into two main components (McEvoy & Mahoney, 2012). Prospective IU refers to information-seeking behaviours and the desire to know for sure what the future holds. In Simon’s case this was in relation to his health, and his efforts to gather information about his diet and any possible illnesses so as to eliminate any chance of ill health. Inhibitory IU is the aspect of IU characterised by avoiding situations that provoke uncertainty in any way- such as Simon’s refusal to eat in situations where he didn’t have complete certainty about the meal’s source.

A Model of IU

A cognitive behavioural model can be used to understand how IU forms and is maintained (e.g., Abramowitz, Deacon, & Whiteside, 2019). This model consists of four steps: negative core beleifs about uncertainty, biased information processing when dealing with ambiguity, threatening interpretations of uncertainty, and unhelpful certainty-seeking behaviours.

Core Beliefs about Uncertainty

All of us have core beliefs- our deeply held sets of rules and assumptions, through which we filter and interpret our experiences. Core beleifs stating that uncertainty is dangerous and that one has to be certain in order to be safe could therefore form a filter through which an individual views all moments of ambiguity or doubt, leading to high levels of distress. In Simon’s case his core beleifs revolved around needing to feel sure he was healthy, and the belief that being uncertain in regards to his diet and health was an unbearable situation that had to be avoided at all costs.

Biased Information Processing

Uncertainty and ambiguity are all around us, all the time. Yet for individuals with IU, biases in the way they process information make the world more uncertain. Individuals with higher IU are likely to view situations as uncertain- and therefore distressing- when other people would view the same situation as being relatively certain (Ladouceur, Talbot, & Dugas, 1997).

Threatening Interpretations of Uncertainty

For most people, a situation where they are “certain enough” that they are safe would probably not provoke any anxiety unless there were specific signs or cues that suggested danger. People with high IU, on the other hand, would view even slightly uncertain situations as threatening. These interpretations lead to individuals with high IU being constantly on alert for nay signs of uncertainty or ambiguity around them. This high level of monitoring makes them more likely to find and focus on potential areas of ambiguity, increasing their overall anxiety levels.

Certainty-Seeking Behaviours

In order to try and manage uncertain situations, people with high IU often engage in unnecessary (and often costly) attempts to find certainty. This can take many forms, depending on the kind of uncertainty and anxiety experienced, but may include seeking reassurance from others, excessive checking and information seeking, or mental rituals. Avoidant behaviours such as being reluctant to try new experiences and indecision when confronted with choices could also be seen as ways to try and reduce uncertainty. Simon’s certainty-seeking actions took the form of checking his symptoms online, as well as seeking reassurance about his diet from his fiancé.

These certainty seeking actions have actually been shown to reduce an individual’s confidence in their own memory: the more you check, the less confident you feel. Thus these actions often end up strengthening feelings on uncertainty.

Negative Reinforcement

Certainty-seeking behaviours may provide temporary relief from uncertainty. In doing so they become habitual, and individuals come to rely on them through a process of negative reinforcement. These behaviours also maintain the individual’s preoccupation with the feared subject and their belief that they need to be certain in order to avoid harm. Over time, Simon comes to believe that his checking his food and constant monitoring of his symptoms is the only thing keeping him safe from harm. The more he engages in certainty-seeking, the more unable to tolerate uncertainty he becomes.


To summarise the model, Simon’s core beliefs about the dangers of being uncertain lead to biases in how he filters the world around him, leading to a lower threshold for perceiving uncertainty in everyday life. When he experiences uncertainty, he interprets this as a threat and as something he needs to avoid, leading to increased anxiety and distress.

To deal with this distress, Simon engages in certainty-seeking behaviours. These behaviours reduce his uncertainty temporarily, since he can never be fully sure he is not getting ill. This temporary relief leads Simon to become increasingly reliant on certainty-seeking actions, increasingly preoccupied with his fears and doubts, and increasingly unable to deal with uncertainty.

For Simon, as for all individuals with high IU, treating his symptoms is not a case of eliminating any sources of uncertainty in his life- this is what he has been trying to do all along and it does not work. Rather, treatment aims to increase his ability to tolerate uncertainty without finding it threatening or relying on certainty-seeking behaviours.

Measuring IU

IU is measured using the Intolerance of Uncertainty Scale (IUS-12; Carleton, Norton, & Asmundson, 2007), a scale for measuring reactions to uncertainty in different situation. Users rate each item on the scale from 1 (not at all characteristic of me) to 5 (entirely characteristic of me). The scale measures both prospective IU and inhibitory IU.

Testing shows that the IUS-12 has good reliability in reliably diagnosing symptoms of IU, and good associations with other tests for symptoms of OCD, general anxiety, and other anxiety disorders. There is no formal diagnosis for having IU as a condition or specific trait, but often individuals being treated for some form of anxiety disorder score around 40 out of 60 on the scale (Carleton, Mulvogue, et al., 2012; Jacoby et al., 2013).

A separate scale, the Intolerance of Uncertainty Index (Carleton, Gosselin, & Asmundson, 2010; Gosselin et al., 2008) has also been developed, aiming to address issues with the IUS-12, such as the fact it may measure the consequences of high IU (such as high avoidance or fear), but not the intolerance of uncertainty itself. The two part, 45-item index aims to assess IU as distinct from the emotional and behavioural responses it produces. Research shows that this scale has excellent consistency and associates well with symptoms of depression and anxiety.

Examples of IU across different forms of anxiety

Examples of IU

Domain of Anxiety Example IU Belief
General Worry I make sure I am fully prepared for any situation
Phobias I avoid dogs at all costs- better safe than sorry
Responsibility for harm I am terrified of leaving the stove on when I go to work, so I check multiple times before leaving
Posttraumatic Stress I may be attacked again if I go back to the same place it happened before, so it’s better to stay away
Social Anxiety If I don’t know whether people like me or not I feel extremely uncomfortable
Body Dysmorphia I seek constant reassurance about how I look
Undesirable Thoughts I don’t know if my thoughts about death may lead to me kill myself one day
Panic Attacks I hate being taken by surprise because fear may cause me to have a heart attack
Illness Anxiety I have to know what my health will be like in the future
Contamination Fears I have to make absolutely sure I’m not picking up germs anywhere
Not “just right” Fears I can’t stop reading until it feels “just right”

Uncertainty about Safety and Danger

Perhaps the most common way IU manifests is in relation to harm and danger befalling oneself and loved ones. This could take the form of worries about every day activities such as driving, going outside or coming into contact with other people- all things which pose a very minor amount of risk and uncertainty. Where most people find this level of risk and uncertainty acceptable, a person with high IU would find their head filled with “what ifs” regarding the possible negative consequences of these mundane activities. This form of IU is common across many forms of anxiety disorder, particular generalised anxiety.

In response to these worries about everyday uncertainty, anxious individuals develop unhelpful certainty-seeking behaviours: excessive reassurance seeking, and avoidance of any decision or situation where uncertainty exists.

IU of this kind may also be present in phobias- as “what if questions” (eg “what if the plane crashes”) or as catastrophic predictions around uncertain situations (eg “I don’t know what the dog will do so I can’t stop it biting me”). Uncertainties about safety can also play a part in OCD- individuals may fear that making a certain action or decision will lead to harm for themselves or their loved ones. For example a man may experience an intrusive thought about his house being burgled if he accidentally left the door unlocked, leading him to doubt whether he really did lock the door or not. He then feels unable to tolerate the uncertainty around whether he did lock the door, and needs to know for certain if he did. People with this form of IU rely on certainty-seeking behaviours such as excessive checking (eg checking the door is locked again and again before leaving the house) or reassurance-seeking (calling home regularly to check everyone is safe).

IU about safety also plays a role in posttraumatic stress disorder. Individuals with PTSD may experience uncertainty about the event itself (eg “could I have dome something differently or avoided what happened?”) or about their future sense of safety (“what if it happens again?”). People with PTSD view the possibility of their trauma recurring as inherently threatening, leading to excessive vigilance and anxiety about future threats. This constant state of high alert actually makes it harder to process your traumatic experiences (White & Gumley, 2009), thereby making the symptoms harder to treat.

Uncertainty about Social Evaluation

Social situations are inherently full of uncertainty- you can never truly know how other people will act around you or how they will respond to your own actions. For individuals with social anxiety, this uncertainty leads to a persistent fear around potential embarrassment or negative evaluation from others.

IU may also be involved in the formation and maintenance of body-dysmorphic disorder (Lavell, Farrell, & Zimmer-Gembeck, 2014; Summers, Matheny, Sarawgi, & Cougle, 2016). For patients with this disorder, the uncertainty lies around how others will view their body, leading to unhelpful certainty-seeking in the form of constantly monitoring and checking their appearance (Phillips, 2005). A common coping strategy for individuals with social anxiety or body dysmorphia is avoidance- since you cannot ever be certain how people will react to you, better to avoid contact with others as much as possible. Uncertainty intolerance may also play a role in how such people ruminate on past social encounters, obsessing over questions such as “did I say the right thing?” “did I upset someone?”.

Uncertainty about Health and Contamination

Uncertainty around your physical health is a common feature in many anxiety disorders. Firstly, individuals with panic disorder are often fearful of the possibility of a future panic attack: since attacks are uncontrollable they naturally pose a great deal of uncertainty (PD; Carleton et al., 2014; Mahoney & McEvoy, 2012; McEvoy & Mahoney, 2012). This uncertainty often revolves specifically around the meaning of internal sensations: “does my racing heart mean I’m having a heart attack?”, “if I start breathing too heavily will I hyperventilate?” and so on. Such physical sensations may be easily understood in some situations, such as a racing heart after intense exercise, but less so in others, and this ambiguity is often a key source of anxiety. Fears around how you will cope with an attack in public or how others will react are also common. Certainty-seeking behaviours such as frequent pulse-checking and other monitoring of bodily states often arise in an attempt to eliminate these uncertainties.

Uncertainty around health more generally can often manifest in Illness Anxiety Disorder (IAD) (Boelen & Carleton, 2012; Deacon & Abramowitz, 2008; Fergus & Valentiner, 2011). Individuals with IAD are often intolerant of any kind of uncertainty about their health, believing that in order to be healthy they have to be totally free of any negative feelings or symptoms. This leads to hyper-vigilance about both external cues (such as news about illnesses or other people getting ill) and internal cues (such as headaches, spots and other unaccounted for symptoms). Being extra vigilant for these symptoms makes these individuals more likely to spot them, and more likely to interpret them catastrophically, often viewing minor or benign symptoms as the onset of some deadly affliction (Olatunji, Deacon, Abramowitz, & Valentiner, 2007). Increased physical arousal caused by these fears further reinforces the belief that something is seriously wrong, and often leads to certainty-seeking behaviours such as intense monitoring of symptoms and constant research or visits to the doctor.

Finally on the subject of uncertainty regarding illness, fears of contamination are a common component of OCD (e.g., Jensen & Heimberg, 2015; Sarawgi, Oglesby, & Cougle, 2013). OCD patients often develop uncertainties about contamination from unclean substances, and the possible future consequences this may bring. This results in certainty-seeking compulsions aimed at de-contamination and removing this risk.

Not “Just Right” Experiences

Uncertainty around not “just right” experiences (NJRE) (Bottesi, Ghisi, Sica, & Freeston, 2017) is a rarer, but still present way that IU can manifest. Individuals with these fears often grapple with the idea of making sure they do things “the right way” and fear stopping or completing tasks in a way that isn’t “just right”. Examples include reading a book and only being willing to finish a page in a certain way, or completing simple tasks in even numbers for fear that to do otherwise would be bad luck.

In this context, uncertainty regards what may happen if actions are not completed just right. Individuals develop beliefs that their just right actions and rituals prevent bad tings happening to themselves or their loved ones. Individuals may be able to see that the link between their NJTE and any future harm is illogical, but still feel that it is better to be safe than sorry and persist in mentally making this link.

Chapter 4: Anxiety Sensitivity

When Alan was just five, he was stung by a wasp while playing in the park with his friends. He suffered a severe allergic reaction causing his face to swell up- his eyelids swelled to the point he could barely see and his throat closed until he struggled to breathe. He was rushed to hospital and treated with adrenaline. Doctors said he was lucky to have survived.

Ever since, Alan has been preoccupied with worries about his health, in particular about allergic reactions. One morning the humid air caused him to struggle to catch his breath. He started to worry that he might be allergic to smog and that this could prove fatal. He started to breathe more quickly- due to his nerves and because he wanted to make sure he was getting enough air. Things only got worse- he started to feel dizzy, his heart began pounding and he started to feel numb. His chest tightened and he struggled to breathe. Terrified he was dying, Alan called for an ambulance, but by the time it arrived, he was fine. There was no allergic reaction- his nerves had caused every symptom he experienced. Even so, he feared that next time he may not be so lucky.


Alan experiences what is known as heightened anxiety sensitivity- an intense fear of the sensations associated with bodily arousal. In effect, he is afraid of the physical effects of being afraid. This fear arises from inaccurate or dysfunctional beleifs about the meaning or significance of these bodily sensations (Reiss, Peterson, Gursky, & McNally, 1986).

AS exists on a continuum of severity. High AS may cause someone to believe that arousal-related physical sensations are dangerous, or a sign that something bad will happen. Examples include beliefs such as “my heart beating too fast is a sign of a heart attack” or “if I start to sweat or tremble, other people will laugh at me”. People with lower levels of AS may interpret these same symptoms as being harmless.

AS is often a compounding factor that exacerbates existing worries. Fears around the physical sensations of fear creates a destructive loop in which feeling anxious creates physical arousal, leading to anxiety, leading to further arousal. AS is therefore a predisposing factor in many forms of mental health disorder, particularly panic disorder, generalised anxiety disorder, and PTSD (Naragon-Gainey, 2010). High AS in individuals with any form of anxiety disorder is often separated into three distinct components: cognitive concerns (the belie that anxious thoughts are harmful or a sign of danger), physical concerns (the belief that physical sensations are harmful, or lead to harm) and social concerns (believing that public displays of anxiety lead to social rejection and other bad outcomes) (Taylor et al., 2007).

Causes of AS

Genetic studies (using twins) show that differences in AS are a combination of genetic and environmental factors (Brown et al., 2012; Taylor, Jang, Stewart, & Stein, 2008). While it is thought that genes associated with high AS are probably linked to the development of areas of the brain associated with processing threat, the exact genes responsible are unknown.

On the environmental side, experiences can teach people that feelings of bodily arousal lead to danger (Knapp, Frala, Blumenthal, Badour, & Leen-Feldner, 2013; Stewart et al., 2001). Alan’s story illustrates this point: when he was a child an experience of strong physical arousal proved nearly fatal, and so even as an adult he continues to fear any remotely similar physical experience. Other ways an individual may learn to fear physical arousal could be though information (being told that certain sensations are dangerous), observation (observing parents taking great care to avoid physical arousal) and possibly Pavlovian conditioning (Stewart et al., 2001).

Measuring AS

An 18-question scale known as the Anxiety Severity Index-3 (ASI-3; Taylor et al., 2007) has been developed to measure levels of AS. The scale is divided into 3 subsections, measuring the three dimensions of AS mentioned above (cognitive, physical and social). Research finds this scale to be both reliable and high validity (e.g., Farris et al., 2015; Kemper & Hock, 2017; Rifkin, Beard, Hsu, Garner, & Björgvinsson, 2015).

Interoceptive Exposure

A process known as interoceptive exposure is often used to assess and reduce AS. During this process, patients are asked to complete exercises that deliberately induce feelings of physical arousal. This can be helpful in identifying which particular feelings and symptoms you are fearful of, and which ones you aim to avoid. For example, after inducing a racing heart by jogging on the spot, you can ask yourself how fearful the feeling of your heart racing makes you, on a scale from one to ten. See below for a list of interoceptive exposure exercises, and the catastrophic beliefs they can test for. The table also includes any known contraindicators- health and safety reasons not to attempt each specific exercise.

Example Interoceptive Exposure Exercises Example Beliefs Contraindicators
Shake head from side to side Dizziness can lead to going crazy Cervical illness or injury, history of balance issues
Place head between knees and then quickly lift up to normal position Light headedness could be a sign of a stroke Postural hypertension, lower back pain, balance issues
Spin around in an office chair, or while standing Feeling nauseous will definitely lead to throwing up Pregnancy, history of falling or balance issues
Hold breath for 30 seconds My chest tightening means I’m having a heart attack Chronic obstructive lung disease
Hyperventilate If I breathe too much, I could collapse Chronic obstructive lung disease, asthma, heart conditions, renal disease, pregnancy
Breathe through a straw without breathing through nose Choking sensations are dangerous to my health Chronic obstructive lung disease
Stare at a ceiling light (for 1 minute) If my visions starts to go weird it means I’m losing my mind History of seizures
Stare into a mirror (for 2 minutes) If I start to feel unreal or spaced out it means I’m losing my mind None
Tense all muscles in the body while sitting People will notice if I start to tremble and will laugh at me Pain disorders
Jog on the spot Racing heart is a sign of a heart attack Cardiac conditions, severe asthma, lower backpain, asthma
Blow hot air into face with a heater or hair dryer It will be unbearably embarrassing if people think I’m having hot flushes None
Place tongue depressor at the back of mouth for 30 seconds If I gag I’ll start to vomit uncontrollably Strong gag reflex
Drink 2-3 cups of coffee I’ll go crazy if I get too jittery History of insomnia or sleep disorders
Start to swallow and then pause mid-swallow for 5-10 seconds My throat feeling tight means I’m about to start choking Strong gag reflex

Reducing AS is one aspect of treating panic disorder, and researchers are investigating how similar treatments could benefit individuals with other disorders. AS also plays a key role in PTSD, so reducing it using interoceptive exposure may be a helpful addition to treatment (Taylor, 2017). Patients with PTSD are often very fearful of any treatment involving confronting their trauma. Interoceptive exposure could be used to reduce AS, thereby paving the way for trauma-related exposure.

Chapter 5: Disgust Sensitivity

Disgust is a basic human emotion felt by all of us, and yet there is a great deal of variation in what disgusts us, and how sensitive we are to potential sources of disgust. Disgusting stimuli can be largely split into three categories: pathogen disgust (including blood, gore, saliva, and so on), moral disgust (induced by ideas such as rape or misuse of power) and sexual disgust (elicited by such things as sexual advances from someone seen as very unappealing) (Tybur, Lieberman, & Griskevicius, 2009; Tybur, Lieberman, Kurzban, & DeScioli, 2013).

The emotion of disgust is useful from an evolutionary point of view. Finding stimuli relating to blood, contamination and illness inherently repellent serves as a means of keeping us motivated to avoid substances which may infect us or make us sick. Disgust is therefore commonly viewed as an evolved mechanism for keeping us safe from infection and disease. The fact that pathogen-related disgust is often focused on contact with skin and body apertures- the intersections between body and outside environment- also supports this notion (Rozin, Nemeroff, Horowitz, Gordon, & Voet, 1995).

Disgust creates a strong desire to distance oneself from the disgusting stimuli. Because of this inherent and powerful urge to avoid anything considered disgusting, simply telling someone that the object of their disgust is in fact totally clean and safe normally does little to change their mind. As an example, imagine you are eating at a restaurant. You are about to eat some soup when a water walks by and drops a maggot into your soup. You probably wouldn’t eat the soup, right? But what if the waiter explained to you that the maggots had been sterilised and couldn’t possibly have any harmful bacteria or germs on them? Would you then be willing to eat the soup? Most people would still say no- knowing that the disgusting maggots are in fact safe does little to change your perception of them as disgusting. The notion that maggots-and all disgusting stimuli- are disgusting is quite separate from whatever risks they may or may not present.

The Laws of Disgust

Disgust operates on a “better safe than sorry” mentality. Better to totally avoid contact with anything potentially disgusting-and therefore harmful- than to risk it and end up harmed as a result. This conservative, safety-first mindset gives rise to two “laws” that shape the disgust response.

The law of similarity states that a new object or stimulus may be seen as disgusting if it is deemed too similar to a known disgusting stimulus. Macaroni may for example be seen as disgusting simply because it looks a bit like maggots to someone who has never seen it before, while a delicious cake that has been made to look rotten and foul using food colouring would be very hard for most people to consider eating (Rozin & Fallon, 1987).

The second law is known as the law of contagion. This rule states that once a disgusting stimulus has come into contact with something, it is contaminated for ever. If a fly lands on your food, even for just a moment, most people would probably discard the affected are or even the entire dish (e.g., Mulkens, de Jong, & Merckelbach, 1996). From a survival perspective, holding this view makes sense- even brief contamination from a highly toxic substance can turn ordinary things deadly. A side effect of this law, however, is that disgust becomes hard to shake once associated with a particular stimuli, and can be easily generalised.

Disgust vs Anxiety

The way that disgust motivates people to avoid contact with disgusting stimuli is similar to the way in which anxiety motivates us to avoid possible sources of harm. Yet there are differences in the motivations fear and disgust produce: fear motivates us to be alert for any potential sources of harm in order to quickly escape, disgust merely motivates us to stay sufficient distance from the possible source of contamination (e.g., Lavy, van den Hout, & Arntz, 1993),. Fear of a spider may cause someone to run away from it; disgust at the presence of a maggot would not cause them to run from it but to simply ensure it doesn’t get too close. This makes sense when you consider the fact that most disgusting stimuli (blood, feces etc) are inanimate or not really capable of movement, so being motivates to actively flee from them is unnecessary.

Another crucial difference between anxiety and disgust is that the rate of decline is much longer for disgust. Feelings of disgust in relation to a specific stimuli do taper off as time goes on, but at a much slower rate than anxiety. This is perhaps due to the fact that it is harder to tell if something is clean and free of contamination (since contaminants like bacteria are harder to see) than it is to determine if something is safe. Despite this, exposure to disgusting stimuli until feelings of disgust have subsided remains a crucial part of overcoming disgust sensitivity.

Disgusting Mental Stimuli

The urge to avoid disgusting stimuli can also relate to disgusting thoughts and memories. People who are particularly sensitive to disgusting memories will often try to avoid or shut them out. This ends up preventing them from properly processing these memories and correcting any unhelpful interpretations or beleifs they have about the memories, getting in the way of recovery.

Disgust in OCD

Greater sensitivity to disgust is strongly linked to forms of OCD which centre around contamination fears and washing compulsions (e.g., Olatunji, Sawchuk, Lohr, & de Jong, 2004; Olatunji, Williams, et al., 2007). Patients with OCD are, unsurprisingly, very sensitive to disgusting stimuli which may pose a source of contamination, and are even sensitive to the more theoretical prospect of becoming contaminated.

Disgust in PTSD

Many traumatic events that lead to PTSD contain some element of disgust. Examples could include wartime experiences and sexual assault. Research suggests that disgust plays a primary role in around 10% of PTSD cases (Power & Fyvie, 2013). For such people, revisiting the trauma memory elicits feelings of disgust. People whoa re highly disgust-sensitive would be especially motivated to avoid facing these memories, leading to impaired recovery as mentioned above.


It is clear that disgust and disgust-sensitivity need to be considered in any attempt to understand clinical anxiety. Looking at both disgust and anxiety can shed light on different aspects of anxiety disorders, and help us to understand why they persist. Ways in which disgust impacts anxiety is an important rea of future research.



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Dugas, M. J., Buhr, K., & Ladouceur, R. (2004). The role of intolerance of uncertainty in etiology and maintenance. In R. G. Heimberg, C. L. Turk, & D. S. Mennin (Eds.), Generalized anxiety disorder: Advances in research and practice (pp. 143–163). New York,NY: Guilford Press.

Dugas, M. J., Gagnon, F., Ladouceur, R., & Freeston, M. H. (1998). Generalized anxiety disorder: A preliminary test of a conceptual model. Behaviour Research and Therapy36, 215–226.

Dugas, M. J., Gosselin, P., & Ladouceur, R. (2001). Intolerance of uncertainty and worry: Investigating specificity in a nonclinical sample. Cognitive Therapy and Research, 25, 551–558.

Dugas, M. J., Hedayati, M., Karavidas, A., Buhr, K., Francis, K., & Phillips, N. A. (2005). Intolerance of uncertainty and information processing: Evidence of biased recall and interpretations. Cognitive Therapy and Research, 29, 57–70.


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Dugas, M. J., Schwartz, A., & Francis, K. (2004). Intolerance of uncertainty, worry, and depression. Cognitive Therapy and Research, 28, 835–842.

Einstein, D. A. (2014). Extension of the transdiagnostic model to focus on intolerance of uncertainty: A review of the literature and implications for treatment. Clinical Psychology: Science and Practice, 21, 280–300.

Fergus, T. A., & Valentiner, D. P. (2011). Intolerance of uncertainty moderates the relationship between catastrophic health appraisals and health anxiety. Cognitive Therapy and Research, 35, 560–565.

Fetzner, M. G., Horswill, S. C., Boelen, P. A., & Carleton, R. N. (2013). Intolerance of uncertainty and PTSD symptoms: Exploring the construct relationship in a community sample with a heterogeneous trauma history. Cognitive Therapy and Research, 37, 725–734.

Freeston, M. H., Rhéaume, J., Letarte, H., Dugas, M. J., & Ladouceur, R. (1994). Why do people worry? Personality and Individual Differences, 17, 791–802.

Gentes, E. L., & Ruscio, A. M. (2011). A meta-analysis of the relation of intolerance of uncertainty to symptoms of generalized anxiety disorder, major depressive disorder, and obsessive-compulsive disorder. Clinical Psychology Review, 31, 923–933.

Gosselin, P., Ladouceur, R., Evers, A., Laverdière, A., Routhier, S., & Tremblay-Picard, M. (2008). Evaluation of intolerance of uncertainty: Development and validation of a new self-report measure. Journal of Anxiety Disorders, 22, 1427–1439.

Grenier, S., & Ladouceur, R. (2004). Manipulation de l’intolérance a l’incertitude et inquiétudes. [Manipulation of Intolerance of Uncertainty and worries]. Canadian Journal of Behavioural Science/Revue Canadienne Des Sciences Du Comportement, 36(1), 56–65.

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Jacoby, R. J., Abramowitz, J. S., Buck, B. E., & Fabricant, L. E. (2014). How is the Beads Task related to intolerance of uncertainty in anxiety disorders? Journal of Anxiety Disorders, 28, 495–503.

Jacoby, R. J., Fabricant, L. E., Leonard, R. C., Riemann, B. C., & Abramowitz, J. S. (2013). Just to be certain: Confirming the factor structure of the intolerance of uncertainty scale in patients with obsessive-compulsive disorder. Journal of Anxiety Disorders, 27, 535–542.

Jensen, D., & Heimberg, R. G. (2015). Domain-specific intolerance of uncertainty in socially anxious and contamination-focused obsessive-compulsive individuals. Cognitive Behaviour Therapy, 44(1), 54–62. 2014.959039

Jensen, D., Kind, A. J., Morrison, A. S., & Heimberg, R. G. (2014). Intolerance of uncertainty and immediate decision-making in high-risk situations. Journal of Experimental Psychopathology, 5, 178–190.

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Ladouceur, R., Gosselin, P., & Dugas, M. J. (2000). Experimental manipulation of intolerance of uncertainty: A study of a theoretical model of worry. Behaviour Research and Therapy, 38, 933–941.

Ladouceur, R., Talbot, F., & Dugas, M. J. (1997). Behavioral expressions of intolerance of uncertainty in worry. Experimental findings. Behavior Modification, 21, 355–371.

Lavell, C. H., Farrell, L. J., & Zimmer-Gembeck, M. J. (2014). Do obsessional belief domains relate to body dysmorphic concerns in undergraduate students? Journal of Obsessive-Compulsive and Related Disorders, 3, 354–358.

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McEvoy, P. M., & Mahoney, A. E. J. (2012). To be sure, to be sure: Intolerance of uncertainty mediates symptoms of various anxiety disorders and depression. Behavior Therapy, 43, 533–545.

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Obsessive Compulsive Cognitions Working Group. (2001). Development and initial validation of the obsessive beliefs questionnaire and the interpretation of intrusions inventory. Behaviour Research and Therapy, 39, 987–1006.

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Olatunji, B. O., Deacon, B. J., Abramowitz, J. S., & Valentiner, D. P. (2007). Body vigilance in nonclinical and anxiety disorder samples: Structure, correlates, and prediction of health concerns. Behavior Therapy, 38, 392–401.

Phillips, K. A. (2005). The broken mirror: Understanding and treating body dysmorphic disorder (Rev expanded ed.). Oxford, England: Oxford University Press.

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Sexton, K. A., Norton, P. J., Walker, J. R., & Norton, G. R. (2003). Hierarchical model of generalized and specific vulnerabilities in anxiety. Cognitive Behaviour Therapy, 32, 82–94.

Shikatani, B., Antony, M. M., Cassin, S. E., & Kuo, J. R. (2016). Examining the role of perfectionism and intolerance of uncertainty in postevent processing in social anxiety disorder. Journal of Psychopathology and Behavioral Assessment, 38, 297–306.

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Summers, B. J., Matheny, N. L., Sarawgi, S., & Cougle, J. R. (2016). Intolerance of uncertainty in body dysmorphic disorder. Body Image, 16, 45–53.

Thibodeau, M. A., Carleton, R. N., Gómez-Pérez, L., & Asmundson, G. J. G. (2013). “What if I make a mistake?” Intolerance of uncertainty is associated with poor behavioral performance. Journal of Nervous and Mental Disease, 201, 760–766.

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Tolin, D. F., Abramowitz, J. S., Brigidi, B. D., Amir, N., Street, G. P., & Foa, E. B. (2001). Memory and memory confidence in obsessive-compulsive disorder. Behaviour Research and Therapy, 39, 913–927.

Tolin, D. F., Abramowitz, J. S., Brigidi, B. D., & Foa, E. B. (2003). Intolerance of uncertainty in obsessive-compulsive disorder. Journal of Anxiety Disorders, 17, 233–242.

Tolin, D. F., Brady, R. E., & Hannan, S. (2008). Obsessional beliefs and symptoms of obsessive-compulsive disorder in a clinical sample. Journal of Psychopathology and Behavioral Assessment, 30(1), 31–42.

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Chapter 4: Anxiety Sensitivity

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Boettcher, H., Brake, C. A., & Barlow, D. H. (2016). Origins and outlook of interoceptive exposure. Journal of Behavior Therapy and Experimental Psychiatry, 53, 41–51.

Boswell, J. F., Farchione, T. J., Sauer-Zavala, S., Murray, H. W., Fortune, M. R., & Barlow, D. H. (2013). Anxiety sensitivity and interoceptive exposure: A transdiagnostic construct and change strategy. Behavior Therapy, 44, 417–431.

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Chambless, D. L., Caputo, G. C., Bright, P., & Gallagher, R. (1984). Assessment of fear of fear in agoraphobics: The body sensations questionnaire and the agoraphobic cognitions questionnaire. Journal of Consulting and Clinical Psychology, 52, 1090–1097.

Chambless, D. L., & Gracely, E. J. (1989). Fear of fear and the anxiety disorders. Cognitive Therapy and Research, 13, 9–20.

Clark, D. M. (1986). A cognitive approach to panic. Behaviour Research and Therapy, 24, 461–470.

Clark, D. M. (1989). Anxiety states: Panic and generalized anxiety. In K. Hawton, P. M. Salkovskis, J. Kirk, & D. M. Clark (Eds.), Cognitive behaviour therapy for psychiatric problems: A practical guide (pp. 52–96). New York, NY: Oxford University Press.

Clark, D. M., Salkovskis, P. M., Öst, L.-G., Breitholtz, E., Koehler, K. A., Westling, E., Gelder, M. (1997). Misinterpretation of body sensations in panic disorder. Journal of Consulting and Clinical Psychology, 65, 203–213.

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Reiss, S., Peterson, R. A., Taylor, S., Schmidt, N., & Weems, C. F. (2008). Anxiety Sensitivity Index consolidated user manual: ASI, ASI-3, and CASI. Worthington, OH: IDS.

Rifkin, L. S., Beard, C., Hsu, K. J., Garner, L., & Björgvinsson, T. (2015). Psychometric properties of the anxiety sensitivity index-3 in an acute and heterogeneous treatment sample. Journal of Anxiety Disorders, 36, 99–102.

Schmidt, N. B., Capron, D. W., Raines, A. M., & Allan, N. P. (2014). Randomized clinical trial evaluating the efficacy of a brief intervention targeting anxiety sensitivity cognitive concerns. Journal of Consulting and Clinical Psychology, 82, 1023–1033.

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Smits, J. A. J., Berry, A. C., Tart, C. D., & Powers, M. B. (2008). The efficacy of cognitive behavioral interventions for reducing anxiety sensitivity: A meta-analytic review. Behaviour Research and Therapy, 46, 1047–1054.

Stewart, S. H., Taylor, S., Jang, K. L., Cox, B. J., Watt, M. C., Fedoroff, I. C., & Borger, C. (2001). Causal modeling of relations among learning history, anxiety sensitivity, and panic attacks. Behaviour Research and Therapy, 39, 443–456.

Taylor, S. (2000). Understanding and treating panic disorder: Cognitive-behavioural approaches. New York, NY: Wiley.

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Taylor, S. (2019). Treating anxiety sensitivity in adults with anxiety and related disorders. In J. Smits, M. Otto, M. Powers, & S. Baird (Eds.), Anxiety sensitivity: A clinical guide to assessment and treatment (pp. 55–75). New York, NY: Elsevier.

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Taylor, S., Zvolensky, M. J., Cox, B. J., Deacon, B., Heimberg, R. G., Ledley, D. R., Cardenas, S. J. (2007). Robust dimensions of anxiety sensitivity: Development and initial validation of the Anxiety Sensitivity Index-3. Psychological Assessment, 19, 176–188.

Wald, J., & Taylor, S. (2008). Responses to interoceptive exposure in people with posttraumatic stress disorder (PTSD): A preliminary analysis of induced anxiety reactions and trauma memories and their relationship to anxiety sensitivity and PTSD symptom severity. Cognitive Behaviour Therapy, 37, 90–100.

Wald, J., & Taylor, S. (2010). Implementation and outcome of combining interoceptive exposure with trauma-related exposure therapy in a patient with combat-related post-traumatic stress disorder. Clinical Case Studies, 9, 243–259.

Walker, J. R., & Furer, P. (2008). Interoceptive exposure in the treatment of health anxiety and hypochondriasis. Journal of Cognitive Psychotherapy, 22, 366–378.

Wenzel, A., Sharp, I. R., Brown, G. K., Greenberg, R. L., & Beck, A. T. (2006). Dysfunctional beliefs in panic disorder: The Panic Belief Inventory. Behaviour Research and Therapy, 44, 819–833.

Zvolensky, M. J., Bogiaizian, D., Salazar, P. L., Farris, S. G., & Bakhshaie, J. (2014). An anxiety sensitivity reduction smoking-cessation program for Spanish-speaking smokers (Argentina). Cognitive and Behavioral Practice, 21, 350–363.

Chapter 5: Disgust Sensitivity

Arntz, A., Lavy, E., van den Berg, G., & van Rijsoort, S. (1993). Negative beliefs of spider phobics: A psychometric evaluation of the Spider Phobia Beliefs Questionnaire. Advances in Behaviour Research and Therapy, 15, 257–277.

Askew, C., Çakır, K., Põldsam, L., & Reynolds, G. (2014). The effect of disgust and fear modeling on children’s disgust and fear for animals. Journal of Abnormal Psychology, 123, 566–577.

Badour, C. L., & Feldner, M. T. (2018). The role of disgust in posttraumatic stress: A critical review of the empirical literature. Journal of Experimental Psychopathology, 3, 1–26.

Badour, C. L., Feldner, M. T., Babson, K. A., Blumenthal, H., & Dutton, C. E. (2013). Disgust, mental contamination, and posttraumatic stress: Unique relations following sexual versus non-sexual assault. Journal of Anxiety Disorders, 27, 155–162.

Bar-Anan, Y., & Nosek, B. A. (2014). A comparative investigation of seven indirect attitude measures. Behavior Research Methods, 46, 668–688.

Bixler, R. D., Carlisle, C. L., Hammitt, W. E., & Floyd, M. F. (1994). Observed fears and discomforts among urban students on field trips to wildland areas. The Journal of Environmental Education, 26, 24–33.

Bixler, R. D., & Floyd, M. F. (1999). Hands on or hands off? Disgust sensitivity and preference for environmental education activities. The Journal of Environmental Education, 30, 4–11.

Borg, C., & de Jong, P. J. (2012). Feelings of disgust and disgust-induced avoidance weaken following induced sexual arousal in women. PLoS One, 7, e44111.

Borg, C., de Jong, P. J., & Schultz, W. W. (2010). Vaginismus and dyspareunia: Automatic vs. deliberate disgust responsivity. Journal of Sexual Medicine, 7, 2149–2157.

Bosman, R. C., Borg, C., & de Jong, P. J. (2016). Optimizing extinction of conditioned disgust. PLoS One, 11, e0148626.

Curtis, V., de Barra, M., & Aunger, R. (2011). Disgust as an adaptive system for disease avoidance behaviour. Philosophical Transactions of the Royal Society of London: Series B. Biological Sciences, 366, 389–401.

Davey, G. C. L., Forster, L., & Mayhew, G. (1993). Familial resemblances in disgust sensitivity and animal phobias. Behaviour Research and Therapy, 31, 41–50.

de Jong, P. J. (2013). Learning mechanisms in the acquisition of disgust. In D. Hermans, Rimé & B. Mesquita (Eds.), Changing emotions (pp. 74–80). London, England: Psychology Press.

de Jong, P. J., Andrea, H., & Muris, P. (1997). Spider phobia in children: Disgust and fear before and after treatment. Behaviour Research and Therapy, 35, 559–562.

de Jong, P. J., & Merckelbach, H. (1998). Blood-injection-injury phobia and fear of spiders: Domain specific individual differences in disgust sensitivity. Personality and Individual Differences, 24, 153–158.

de Jong, P. J., & Muris, P. (2002). Spider phobia: Interaction of disgust and perceived likelihood of involuntary physical contact. Journal of Anxiety Disorders, 16, 51–65.

de Jong, P. J., Peters, M., & Vanderhallen, I. (2002). Disgust and disgust sensitivity in spider phobia: Facial EMG in response to spider and oral disgust imagery. Journal of Anxiety Disorders, 16, 477–493.

de Jong, P. J., Vorage, I., & van den Hout, M. A. (2000). Counterconditioning in the treatment of spider phobia: Effects on disgust, fear and valence. Behaviour Research and Therapy, 38, 1055–1069.

Elwood, L. S., & Olatunji, B. O. (2009). A cross-cultural perspective on disgust. In Olatunji & D. McKay (Eds.), Disgust and its disorders: Theory, assessment, and treatment (pp. 99–122). Washington, DC: American Psychological Association.

Engelhard, I. M., Olatunji, B. O., & de Jong, P. J. (2011). Disgust and the development of posttraumatic stress among soldiers deployed to Afghanistan. Journal of Anxiety Disorders, 25, 58–63.

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Fergus, T. A., & Valentiner, D. P. (2009). The Disgust Propensity and Sensitivity Scale–Revised: An examination of a reduced-item version. Journal of Anxiety Disorders, 23, 703–710.

Fiedler, K., Messner, C., & Bluemke, M. (2006). Unresolved problems with the “I,” the “A,” and the “T”: A logical and psychometric critique of the Implicit Association Test (IAT). European Review of Social Psychology, 17, 74–147.

Foy, D. W., Sipprelle, R. C., Rueger, D. B., & Carroll, E. M. (1984). Etiology of posttraumatic stress disorder in Vietnam veterans: Analysis of premilitary, military, and combat exposure influences. Journal of Consulting and Clinical Psychology, 52, 79–87.

Frijda, N. H. (2006). The laws of emotion. Mahwah, NJ: Erlbaum.

Gawronski, B., & Bodenhausen, G. V. (2006). Associative and propositional processes in evaluation: An integrative review of implicit and explicit attitude change. Psychological Bulletin, 132, 692–731.

Gerull, F. C., & Rapee, R. M. (2002). Mother knows best: Effects of maternal modelling on the acquisition of fear and avoidance behaviour in toddlers. Behaviour Research and Therapy, 40, 279–287.

Goetz, A. R., Cougle, J. R., & Lee, H. J. (2013). Revisiting the factor structure of the 12-item Disgust Propensity and Sensitivity Scale—Revised: Evidence for a third component. Personality and Individual Differences, 55, 579–584.

Greenwald, A. G., McGhee, D. E., & Schwartz, J. L. K. (1998). Measuring individual differences in implicit cognition: The implicit association test. Journal of Personality and Social Psychology, 74, 1464–1480.

Haidt, J., McCauley, C., & Rozin, P. (1994). Individual differences in sensitivity to disgust: A scale sampling seven domains of disgust elicitors. Personality and Individual Differences, 16, 701–713.

Huijding, J., & de Jong, P. J. (2007). Beyond fear and disgust: The role of (automatic) contamination-related associations in spider phobia. Journal of Behavior Therapy and Experimental Psychiatry, 38, 200–211.

Jung, K., & Steil, R. (2013). A randomized controlled trial on cognitive restructuring and imagery modification to reduce the feeling of being contaminated in adult survivors of childhood sexual abuse suffering from posttraumatic stress disorder. Psychotherapy and Psychosomatics, 82, 213–220.

Lavy, E., van den Hout, M., & Arntz, A. (1993). Attentional bias and facilitated escape: A pictorial test. Advances in Behaviour Research and Therapy, 15, 279–289.

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