A contemporary learning theory perspective on the etiology of anxiety disorders: It’s not what you thought it was
Article by: Mineka, S. & Zinbarg, R. (2006)
American Psychologist, 61, 10-26

Specific phobia  

Individuals with specific phobias show intense and irrational fears of certain objects or situations that they usually go to great lengths to avoid.

Vicarious conditioning of fears and phobias

Strong and persistent phobias can be learned rapidly through observation alone.

Sources of individual differences in the acquisition of fears and phobias

Many individuals who do undergo traumatic experiences do not develop phobias. From a diathesis-stress perspective, such findings are expected. There seems to be a modest genetically based vulnerability for phobias. This genetic vulnerability may well be mediated through genetic contributions to fear conditioning, which may in turn be mediated through personality variables such as high treat anxiety that also seem to serve as vulnerability factors, affecting the speed and strength of conditioning.

Differences in life experiences among individuals can also strongly affect the outcome of conditioning experiences. Such experiential factors may serve as vulnerability (or invulnerability) factors for the development of phobias. The relevant differences in life experiences may occur before, during, or following a fear-conditioning experience, and they can act singly or in combination to affect how much fear is experienced, acquired, or maintained over time.

Impact of prior experiences

Latent inhibition demonstrates that simple prior exposure to a conditioned stimulus (CS) before the conditioned and unconditioned stimulus (US) are ever paired together reduces the amount of subsequent conditioning to the CS when paired with the US.

A person’s history of control over important aspects of his or her environment is another important experiential variable strongly affecting reactions to frightening situations. A greater sense of mastery and control may lead to a more readily adaption to frightening events and novel anxiety-provoking situations.

Impact of contextual variables during conditioning

Several different features of conditioning events themselves have a strong impact on how fear is acquired. Having control over a traumatic event (such as being able to escape it) has a major impact on how much fear is conditioned to CSs paired with that trauma. Far less fear is conditioned when the aversive event is escapable than when it is not.

Impact of postevent variables

Different kinds of experiences that people can have following conditioning affect the strength of the conditioned fear that is maintained over time. A person who is exposed to a more intense traumatic experience (not paired with the CS) after conditioning of a mild fear is likely to show an increase in fear with the CS.

A US revaluation process can occur when a person receives verbally or socially transmitted information about the US being more dangerous than when she or he originally experienced it paired with the US. This can result in an inflated level of fear to the CS.

Simple mental rehearsal of CS-US relationships can lead to enhanced strength of the conditioned fear response.

Selective associations in the conditioning of fears and phobias

The content of most phobias is rated by independent raters as ‘prepared’ in the sense that it was probably dangerous to pretechnological humans. Prepared fears are not seen as inborn or innate but rather as very easily acquired and/or especially resistant to extinction.

Fear-relevant CSs (but not fear-irrelevant CSs), conditioning can even occur when subliminal CSs are used (CSs that cannot be consciously identified). Fear learning with fear-relevant stimuli is more impenetrable to conscious cognitive control than is fear learning with fear-irrelevant stimuli. If the fears of individuals with phobias arise automatically from cognitive structures not under the control of conscious intentions, the fears will remain unaffected by rational analysis.

In both monkeys and humans evolutionary fear-relevant stimuli more readily enter into selective associations with aversive events, and these same stimuli seem more likely than others to become the objects of human phobias. The special characteristics of fear learning seen with fear-relevant (but not fear-irrelevant) stimuli (its automaticity and its resistance to higher cognitive control) suggest that the acquisition of phobias involves a primitive basic emotional level of learning that humans share with other mammalian species.

Social phobia

Individuals with social phobias show excessive fears of situations in which they might be evaluated or judged by others, and they either avoid such situations or endure them with marked distress.

Several theorists have suggested that social phobia can arise as a result of direct traumatic conditioning.

Social learning and social phobia

Another potentially important pathway to the development of social phobia is through social learning. Vicarious conditioning (observing another being ridiculed or humiliated or behaving in a very anxious way in some social situation) is one potent form of social learning that may be sufficient to make the observer develop social phobia of similar situations.

Direct social reinforcement and verbal instruction are likely to play a role.

Culturally transmitted display rules and norms are another form of social learning that is likely to exert powerful influences on the expression of social anxiety.

Preparedness and social phobia

There is proposed that social anxiety is a by-product of the evolution of dominance hierarchies, and therefore social stimuli signalling dominance and intra-specific threat should be fear-relevant or prepared CSs for social anxiety. It can even be conditioned to subliminal presentations. A person can claim to ‘know’ rationally that a social situation is safe, and yet still experience anxiety that is automatically activated in response to subtle cues that are not consciously processed.

Behavioural inhibition as a temperamental diathesis for social phobia

Not everyone who has experienced a socially traumatic episode or observed a socially anxious model will develop social phobia. As for specific phobias, one source of individual differences involves the temperamental diathesis known as behavioural inhibition, which may influence the outcome of exposure to socially traumatic experiences and/or socially anxious models. Early behavioural inhibition not only predicts the onset of multiple specific phobias in childhood, but also social phobias in adolescence.

Uncontrollability and social phobia

Perceptions of uncontrollability are a likely source of individual differences in vulnerability to the effects of socially traumatic episodes or exposure to socially anxious models. The deleterious effects of social defat are probably mediated by perceptions of uncontrollability. Perceptions of uncontrollability are likely to play a role in the origins of social anxiety. There is an association between perceptions of uncontrollability and social phobia in people.

Panic disorder with and without agoraphobia

People with panic disorder (PD) experience recurrent un-expected panic attacks that occur without their being aware of any cues or triggers, and they must also experience worry, anxiety, or behavioural change related to having another attack. Many people with PD also to on to develop some degree of agoraphobic avoidance of situations in which they perceive that escape might be either difficult or embarrassing if they were to have a panic attack.

Exteroceptive conditioning is where CSs impinge on the external sensory receptors like eyes and ears. Interoceptive conditioning is when the CSs are the body’s own internal sensations.

There is proposed that when low-level somatic sensations of anxiety precede and are paired with higher levels of anxiety/panic, the low-level somatic sensations of anxiety come to elicit high levels of anxiety and panic.

Psychometric analyses of panic- and anxiety-related symptomatology reveal two separable factors 1) Panic is accompanied by strong autonomic arousal, extreme fear, and fight-or-flight action tendencies 2)Anxiety is accompanied by apprehension, worry and tension.

Exteroceptive and interoceptive conditioning in panic disorder

Some argued that the conditioning that may occur in vulnerable individuals during initial panic attacks sets the stage for the development of PD and PDA. The initial attacks become associated with initially neural interoceptive and exteroceptive CSs through conditioning. Because of their status as terrifying emotional events, replete with strong interoceptve stimuli, panic attacks are capable of supporting conditioning. Proposed is that the primary effect of this conditioning is that anxiety becomes conditioned to interoceptive and exteroceptive CSs (heart palpitations and dizziness as well as external cues). Another effect is that panic attacks themselves are likely to be conditioned to certain internal cues.

Different CSs paired with the very same US often result in qualitatively different conditioned responses (CR) to the different CSs.

Some internal and external cues present before and during panic attacks may become conditioned to elicit anxiety (different from the panic unconditioned response (UR)), and others may become conditioned to elicit panic itself. Interoceptive cues in close proximity to panic may serve as ‘prepared’ or fear-relevant CSs and may be especially likely to elicit panic, just as other fear-relevant CSs seem especially likely to condition CRs that strongly resemble URs.

Interoceptive conditioning is robust and stable. Weak versions of some event can become conditioned by pairing it with a strong version of the same event. Early internal signs of panic can become conditioned when paired with full-blown panic attacks.

The development of agoraphobia

As the disorder develops, the agoraphobic fears and avoidance often generalize to other similar situations, as would be expected on the basis of the principles of classical conditioning.

Two major risk factors for developing agoraphobia are 1) Gender, being a women, 2) Employment, people who do not work or who work from home

In each of these factors the person is allowed to avoid his or her feared situations rather than be exposed to them, which would extinguish his or her anxiety.

We might expect that panic attacks perceived as particularly unpredictable and uncontrollable might well lead to the development of greater agoraphobic avoidance because these factors are known to be associated with greater conditioning of anxiety.

Further complexities of the role of conditioning in panic disorder and agoraphobia

Conditioned stimuli not only come to elicit conditioned responses but also to facilitate or inhibit responses controlled by other events.

Conditioned anxiety serves to increase startle responses. It is likely that CSs for anxiety similarly lower the threshold for, or exaggerate, panic reactions. Baseline levels of anxiety strongly predict who will experience panic in response to various panic provocation agents as USs. Anxiety is very often a precursor to (and may potentiate) panic attacks. Because the same CR (anxiety) elicited form two different sources can summate (baseline anxiety and anxiety elicited by a situation) one would expect that baseline anxiety could potentiate agoraphobic anxiety and avoidance.

Vulnerability factors for panic disorder

Three types of vulnerability factors that seem likely to predispose some people who experience panic attacks to develop PD or PDA. 1) A moderate nonspecific genetic vulnerability for PD and PDA. This overlaps with the genetic vulnerability for phobias and may be mediated by temperamental or personality vulnerability factors like neuroticism or trait anxiety. These personality variables serve to potentiate conditioning of anxiety responses as well as aversive expectations. 2) Prior learning experiences that lead to perceptions of lack of control and helplessness. They may serve as psychological vulnerability factors influences the development of panic, agoraphobia and other emotional disorders. Early experience with uncontrollable stressful life events can enhance vulnerability to PD and depression. Early experiences with control and mastery in infancy and childhood are important for developing the ability to cope with stress and anxiety-provoking situations. 3) More specific learning experiences that may play a more unique role in creating risk for developing PD and PDA per se. Observing a lot of physical suffering may contribute to the evaluation of somatic symptoms as dangerous.

Posttraumatic stress disorder

The symptoms of posttraumatic stress disorder (PTSD) include re-experiencing the trauma, passively avoiding reminders of the trauma, numbing of affect, and heightened general arousal. The traumatic event is necessary for the diagnosis is of PTSD.

Animals exposed to uncontrollable and/or unpredictable stress, like individuals with PTSD, show heightened generalized anxiety and arousal. They also show enhanced passive avoidance behaviour. The opioid-mediated analgesia (relative insensitivity to pain) produced by cues associated with uncontrollable stress in animals may resemble certain numbing symptoms seen in PTSD. Fear and distress at exposure to reminders of the trauma can be seen as conditioned emotional responses elicited by reminder cues.

Trauma phase

Traumas that are perceived to be uncontrollable and unpredictable are more likely to result in PTSD. Organisms differ in how they respond to the experience of uncontrollable stress, and such differences can strongly affect the outcome. Survivors with PTSD were more likely than those without PTSD to report having experienced mental defeat during their traumatisation.

Pretrauma phase

Sometimes prior uncontrollable stress sensitizes an organism to the harmful effects of the subsequent exposure to such trauma. As repeated exposures to trauma occur, the adverse effects get larger rather than smaller (habituation). So, a history of prior trauma (especially repeated trauma, which is more likely to be perceived as uncontrollable) should be associated with increased risk of developing PTSD to a recent trauma. Prior trauma is more strongly related to PTSD when the prior trauma involved interpersonal violence.

A prior history of control over stressful events can immunize against the harmful effects of subsequent uncontrollable stress. It can immunize against the development of PTSD to a recent trauma.

Posttrauma phase

The severity of re-experiencing symptoms after a trauma should influence the course of the symptoms of PTSD. Greater re-experiencing are associated with a more persistent course.

The inflation and US reevaluation effects, can affect the course of PTSD. Reinstatement of fear is when after a CS was extinguished, the CS can regain its ability to elicit a CR by simply exposing the animal to the US.

Generalized anxiety disorder

People with generalized anxiety disorder (GAD) are primarily characterized by chronic excessive worry about a number of events or activities for at least six months, and the worry must be experienced as difficult to control.

Several theorists have suggested that uncontrollable and unpredictable aversive events may play an important role in the development of GAD. There is some evidence that people with GAD may be more likely to have a history of childhood trauma than are people with several other anxiety disorders. People with GAD have far less tolerance for uncertainty than do non-anxious controls. This suggests that they are especially disturbed by not being able to predict the future. People with GAD may also have a relative lack of safety signals in their lives, which may help explain why they feel constantly tense and vigilant for possible future threats.

There is evidence that people with extensive experience controlling important aspects of their lives may be immunized against developing GAD.

Most of the perceived benefits of worry centre around people’s beliefs that worry helps avoid catastrophe and deeper emotional topics that they do not want to think about. When people with GAD worry, their emotional and physiological responses to aversive imagery are suppressed. This can serve to reinforce worry. Because worry suppresses physiological responding, this prevents the person from fully experiencing or processing the topic that is being worried about. Such processing is necessary if extinction of an anxiety is to occur. The threatening meaning of the topic will be maintained. Worry might also be reinforced superstitiously because the vast majority of things people worry about never happen. So worry is a cognitive avoidance response.

Worry is not an enjoyable activity and can lead to a greater sense of danger and anxiety because of all the catastrophic outcomes the worrier envisions. It can lead to more negative intrusive thoughts. Attempting to control thoughts and worries may lead to increased experience of intrusive thoughts and enhanced perception of being unable to control them. Perceptions of uncontrollability are associated with increased anxiety, and further intrusive thoughts can serve as trigger topics for more worry. Thus a vicious circle of anxiety, worry, and intrusive thoughts may develop, leading to this sense of being unable to control worry in GAD.

Obsessive-compulsive disorder

The central features of obsessive-compulsive disorder (OCD) are unwanted and intrusive thoughts, impulses, or images that cause marked anxiety or distress. These are usually accompanied by compulsive behaviours or mental rituals that are performed to neutralize or prevent the distressing thoughts or images.

Verbal conditioning and social learning

Verbal transmission of dangerous thoughts may occur. Verbal conditioning may also occur in which a neutral idea is paired with some scary idea that a person may have. Social learning factors may play a role in the greater levels of distress and resistance associated with clinical intrusions. One idea is that parents who encourage a broad sense of responsibility and rigid rules for duty and conduct may create a vulnerability for the development of OCD in the child. Similar factors may lead to beliefs referred as thought-action fusion in which people are taught the idea that thoughts, desires, and impulses are morally equivalent to actions. Another thought-action fusion is the idea that thoughts of a specific catastrophe increase the probability that it will actually occur. Each of these factors may lead to greater distress and attempts to resist intrusions.

Social learning is involved in culturally transmitted beliefs and norms from the teachings of various religions that may exert influences on the expression of some obsessions and compulsions.

The role of avoidance in the maintenance of OCD

Most patients with OCD engage in either behavioural or mental rituals intended to neutralize or prevent their obsessions. Learned avoidance responses are remarkably resistant to extinction.

Preparedness and OCD

The contents of most obsessions and the forms of most compulsive rituals are non-random. The displacement activities that many animal species engage in under situations of conflict or high arousal bear a significant resemblance to the compulsive rituals seen in OCD.