همجوشی فکر-عمل و سرکوب افکار در اختلال وسواس

To examine the significance of thought-action fusion (TAF) and thought suppression tendencies, the present study obtained pre- and post-treatment questionnaire data on these constructs in a sample of OCD patients (n=24) and non-OCD anxiety patients (n=20). Results indicate that TAF and suppression are correlated with severity of psychopathology. Yet, the associations between TAF and psychopathology are not typical for OCD, but do also occur in other anxiety disorders (e.g., panic disorder, post traumatic stress disorder, and social phobia). As well, mean scores on the TAF and thought suppression measures dropped significantly from pre- to post-treatment, indicating that TAF and thought suppression are susceptible to change during psychotherapy.

In their by now classic study, Rachman and De Silva (1978; see also Salkovskis & Harrison, 1984) noted that everyday intrusions and clinical obsessions as seen in obsessive-compulsive disorder (OCD; American Psychiatric Association, 1994) do not differ in content. Differences between both kinds of intrusions do occur, however, with respect to frequency, intensity, discomfort, and elicited resistance, with clinical obsessions being characterised more strongly by these qualities than ‘normal’ intrusions. To account for the similarities and differences between normal and abnormal intrusions, two theories have been invoked. The first emphasises the importance of the interpretation that people give to their intrusions (Rachman, 1993, Rachman, 1997, Rachman, 1998 and Salkovskis, 1985). According to this cognitive theory, obsessional problems may arise when individuals experience an inflated sense of responsibility for their own thoughts. For example, the belief that intrusive thoughts reveal one’s true nature will lead to more discomfort whenever unwanted violent and/or sexual intrusions occur. Such biased appraisals may add obsessive qualities (e.g., increased discomfort, tension, anxiety, and resistance) to intrusive thoughts. Rachman, Thordarson, Shafran and Woody (1995) articulated a refined version of this cognitive account of OCD. According to this version, two types of cognitive bias may be specifically involved in the development of obsessive-compulsive symptoms (see also Emmelkamp & Aardema, 1999). The first bias consists of the tendency to believe that merely thinking about an unpleasant situation (e.g., a car accident) increases the likelihood that this situation will actually occur. This bias is known as the likelihood or probability bias. The second bias consists of the tendency to believe that having immoral thoughts (even involuntary ones) about, for example, violence is as bad as immoral behaviour (e.g., acting violently). This bias is termed morality bias. Together, probability, and morality bias constitute the essential elements of what has been dubbed ‘thought-action fusion’ (TAF; Shafran, Thordarson & Rachman, 1996). In general terms, TAF refers to the tendency to overvalue the significance and consequences of intrusive thoughts. A second theory, addressing the similarities and differences between normal and clinical intrusions focuses on the role of thought suppression in the exacerbation of intrusive thoughts. There is good reason to believe that under some conditions, cognitive avoidance strategies such as thought suppression may be counterproductive. For example, in their often cited studies, Wegner, Schneider, Carter and White (1987) showed that suppression attempts result in more rather than less intrusions. This paradoxical phenomenon is known as the ‘white bear effect’, because Wegner et al. used thoughts of white bears as targets. While the content of this target is, of course, neutral, its heightened frequency is, at least to some extent, reminiscent of obsessional thinking. Most importantly, such a heightened frequency may elicit discomfort. Accordingly, Wegner (1989) claims that the paradoxical effect of thought suppression may result in full blown obsessions: “An obsession can grow from nothing but the desire to suppress a thought” (p. 167). There is some evidence to suggest that both TAF (e.g., Rassin, Merckelbach, Muris & Spaan, 1999) and thought suppression (see Purdon, 1999) are implicated in obsessive-compulsive symptomatology. Some authors have even speculated that TAF and thought suppression may interact in the development of obsessional problems and there are some preliminary results that support this position (Rachman, 1998 and Rassin et al., 2000). However, a number of questions remain to be answered. For example, there is some dispute about the question of whether thought suppression is a causal antecedent of OCD-related symptoms or rather a consequence or part of such symptoms (see Rassin, Merckelbach & Muris, 2000). Furthermore, it is relevant to determine to what extent TAF and suppression tendencies are susceptible to change due to therapeutic intervention. Rachman (1997) emphasises that in the treatment of OCD, changing misinterpretations of intrusions is an important goal: “It follows from the theory that the most direct and satisfactory treatment of obsessions is to assist patients in the modification of the putatively causal catastrophic misinterpretations of the significance of their intrusive thoughts. Bluntly, if these misinterpretations are ‘corrected’, the obsession should cease” (p. 799). As to thought suppression, it should be noted that Wegner and Zanakos (1994) tend to think of this mental control strategy as a stable, trait-like coping style. In their words: “self-reports of thought suppression are reliable over time and thus fulfill an important criterion for recognition as a trait” (p. 624). By this view, thought suppression tendencies should be resistant to change. In the present study, the significance of TAF and thought suppression was examined by administering self-report instruments to OCD-patients prior to and after therapy. If TAF and thought suppression tendencies act as important determinants of obsessional problems, one would expect that pre-treatment scores on questionnaires tapping these phenomena predict symptom severity and, perhaps, treatment efficacy. Also, if TAF and thought suppression are trait-like phenomena, one would anticipate that pre- and post-treatment scores on these questionnaires remain fairly constant.