یک تحقیق تجربی از نقش رفتارهای ایمنی جویی در نگهداری از اختلال هراس با موقعیت هراسی

This study evaluates the hypothesis that safety-seeking behaviours play an important role in maintaining anxiety because they prevent patients from benefiting from disconfirmatory experience. Patients suffering from panic disorder with agoraphobia carried out a behaviour test, closely followed by an experimental session, which included a brief (15 min) period of exposure during which participants either stopped or maintained within-situation safety-seeking behaviours. When the behaviour test was repeated within two days, patients who had stopped their safety-seeking behaviours during the experimental session showed a significantly greater decrease in catastrophic beliefs and anxiety than those who had maintained safety-seeking behaviour. This difference was also reflected in questionnaires measuring clinical anxiety. These results are consistent with the cognitive hypothesis.

The link between anxiety, panic and agoraphobic avoidance has received considerable attention over the past two decades. Behavioural approaches to the understanding and treatment of agoraphobia have largely focused on two process theory (Mowrer, 1960). According to this view, the development of avoidance is crucial to the persistence of classically conditioned agoraphobic anxiety by both preventing and prematurely terminating exposure to the CS and thereby preventing the extinction of conditioned fear responses. This behavioural theory provided the rationale for the development and implementation of exposure treatments ( Mathews, Gelder, & Johnston, 1981; Rachman, 1990), which were found to be highly effective in reducing phobic anxiety. More recently, two process theory has come under critical scrutiny both from within behaviour therapy and from those advocating a biological approach to the understanding and treatment of anxiety. Rachman (1976) questioned the theoretical utility of two process theory. He went on to question the central notion that escape behaviour strengthens subsequent avoidance in experimental studies (Rachman, Craske, Tallman, & Solyom, 1986). From a different perspective, others such as Marks (1987) suggest that learning theory approaches add nothing to the understanding and application of exposure treatments. Marks proposes instead that the “exposure principle” is all that is required to conceptualise fear reduction techniques, and that the questions which remain should primarily focus on how better to deliver exposure treatments. Biological theories have emphasised the hypothesis that although agoraphobic behaviour consequence of panic attacks or panic-like symptoms (Gorman, Liebowitz, Fyer, & Stein, 1989) it is not a key factor in prolonging panic. Avoidance behaviour is a response to panic attacks, and secondary to them. When full panic attacks are not present, it is hypothesised that “panic-like symptoms” drive the avoidant behaviour. This way of viewing agoraphobia contrasts sharply with behavioural theories, and suggests that the main focus of treatment should be on the panic attacks and panic-like symptoms, with direct attention to agoraphobia only if avoidance does not fully remit once the panic symptoms have been dealt with. Given that exposure is known to be effective in the treatment of agoraphobia with panic disorder (Mathews, Gelder & Johnston, 1981), neither the behavioural nor the biological approach adequately explain the mechanism by which exposure has its effects. To develop more effective fear reduction techniques, a theoretical understanding of the psychological mechanisms involved when exposure results in fear reduction is therefore required. The passing of the two stage theory of phobic avoidance has left a theoretical gap which, if not filled, is likely to hamper the further development of more effective psychological treatments for anxiety problems. The cognitive-behavioural theory of anxiety provides a coherent general account of the occurrence and maintenance of anxiety problems and can explain the effectiveness of exposure-based treatments. According to the cognitive-behavioural theory (Beck, 1976; Beck, Emery, & Greenberg, 1985; Clark, 1986b; Salkovskis, 1996), anxiety disorders arise when situations are perceived as more dangerous than they really are. Once such a threat is (mis)perceived, at least three mechanisms may be involved in the maintenance of persistent high levels of anxiety; selective attention to threat-relevant stimuli, physiological arousal and safety-seeking behaviours. (The latter include avoidance and escape behaviour; as explained below they may also include other mechanisms.) Each of these reactions may occur as a response to threat and anxiety, and they may serve to amplify or maintain the crucial threat beliefs. The cognitive theory suggests that, in phobic anxiety, safety-seeking behaviour is particularly important in the maintaining perceived threat. The present paper describes an investigation of this factor in patients suffering from panic disorder with agoraphobia, building on the cognitive theory of panic (Clark, 1986a and Clark, 1988). The agoraphobic believes that entering situations such as crowded shops is likely to result in some catastrophic physical or mental harm. The catastrophes most commonly feared during a panic attack include passing out, having a heart attack, going crazy, losing control over their behaviour (Clark, 1986a and Clark, 1986b. Such beliefs about the effects of entering agoraphobic situations are not justified, since the person does not pass out, have a heart attack, lose control, go insane and so on. Why, then, do the beliefs persist despite repeated disconfirmation? The cognitive hypothesis proposes specific links between panic and avoidance which override the effect of the objective disconfirmations. If panic patients misinterpret a situation (e.g. the occurrence of intense bodily sensations) in a way which leads them to expect an imminent disaster, they will behave in a way that is intended to avert the feared disaster. Thus they not only avoid the situation but also the feared outcome; since the feared outcomes differ between patients, so do the behaviours they adopt to evade them. It is not anxiety which is avoided and escaped, nor the situation, but catastrophes which the person believes are about to occur. In a study of panic patients ( Salkovskis, Clark, & Gelder, 1996), the interpretations patients made during panic attacks and the safety-seeking behaviours they attempted to deploy in those attacks were found to be related in the way predicted by cognitive theory. For example, patients who reported that, during a panic attack, they believed that they were going to pass out were more likely to hold on to people or objects than were those who did not have such a belief. Similarly, only patients who were afraid of being paralysed with fear reported trying to exercise more during panic, and so on. The scope of avoidance can thus be regarded as broader than generally encompassed by behavioural descriptions (e.g. Marks, 1987), with both kinds of avoidance playing a major role in the maintenance of panic attacks (Salkovskis, 1988 and Salkovskis, 1991). The patient who interprets a weak feeling in the legs as a sign that he may collapse attempts to prevent collapse by holding on to nearby objects, tensing his legs and seeking a seat. By doing so, he prevents disconfirmation of his fear of collapse. Patients are often unaware of the anxiety maintaining effects of their avoidant behaviour (described here as safety-seeking behaviour). Thus, the subjective impact of their behaviour is to transform an incident which could have provided a disconfirmation of their fears into evidence maintaining their negative interpretation of symptoms. These patients believe that they have experienced a “near miss” and may say “If I had not prevented it by tensing my legs, then I would certainly have collapsed”. The cognitive hypothesis predicts an internally logical match between such beliefs and behaviours during panic; for example, fears of loss of control should be associated with attempts to control oneself, and this is what was found by Salkovskis et al. (1996). Similar considerations can be applied to more generalised forms of avoidance and escape behaviour; an agoraphobic who decides not to go shopping on a particular day may conclude “It's lucky I did not go, otherwise I would have had an enormous panic; if I had panicked today, I would certainly have collapsed”. Once again, avoidance has “prevented” collapse. However, these types of avoidance behaviours are only logically possible when the feared catastrophe has external correlates; that is, leaving a situation has only limited value as a strategy for dealing with an impending heart attack. The main usefulness of such a strategy would be in situations where social evaluative concerns predominate; removing oneself from other people is a helpful strategy both as catastrophe avoidance and removing the person from the scrutiny of others. As panic and avoidance become more chronic, the behaviours involved become habitual and awareness of the specific cognitive component diminishes although it can often be produced by further exposure. Often patients express their fears as a desire to escape; for example, when asked what went through their mind in a phobic situation, patients typically respond “I just had to get out”. The particular belief is readily revealed by asking what, at that time, would he have though the worst thing that could have happened should he be unable to get out. Thus, the cognitive analysis of avoidance involves an analysis of what outcome the patient is avoiding rather than just of the anxiety arousal/relief associated with the specific situation. Cognitive theory predicts that safety-seeking behaviours have the effect of maintaining anxiety-generating beliefs because patients infer that they have prevented the occurrence of feared catastrophes by their behaviour. The experiment described here is designed as a direct test of this prediction by examining the effect of safety-seeking behaviours in panic disorder with agoraphobia. Exposure to feared situations was compared under two conditions. In one condition patients are encouraged to maintain their safety-seeking behaviours, in the other they are encouraged to intentionally stop them. It was predicted that the latter would disconfirm their negative beliefs.