اثرات واسطه سوء تعبیر از افکار مزاحم بر علائم وسواسی جبری

Perfectionism and inflated responsibility have both been identified as risk factors for the development and maintenance of obsessive-compulsive (OC) symptoms. The aim of the present study was to test whether the relationships between these two variables and OC symptoms are mediated by the misinterpretation of intrusive thoughts (MIT). Three hundred and three university students completed the Frost Multidimensional Perfectionism Scale, the Maudsley Obsessional Compulsive Inventory, the Responsibility Attitude Scale, and the Responsibility Interpretations Questionnaire. MIT was found to partially mediate the relationship between responsibility attitudes and OC symptoms. MIT also partially mediated the relationship between concern over mistakes and OC symptoms, even after controlling for responsibility attitudes. Both concern over mistakes and responsibility attitudes were significant predictors of MIT and OC symptoms, but responsibility was the stronger predictor when all of the variables were included in the model. Clinical implications for the treatment of OCD are discussed.

The Obsessive Compulsive Cognitions Working Group (OCCWG, 1997) has proposed several cognitive variables that play an important role in the aetiology and maintenance of obsessive-compulsive disorder (OCD). These variables include inflated responsibility, perfectionism, beliefs concerning the over-importance of thoughts, excessive concern about the importance of controlling one's thoughts, overestimation of the probability and severity of threat, and intolerance for uncertainty. Of these six variables, inflated responsibility (originally postulated by Salkovskis, 1985) is the one that has received the greatest empirical and theoretical attention in recent years. Salkovskis’ model of the development and maintenance of OCD (as presented in Salkovskis, Forrester, & Richards, 1998) is based on the assumption that intrusive thoughts are a normal phenomena and that OC symptoms arise as a result of misinterpretation of these thoughts. The theory suggests that early experiences lead to assumptions and general beliefs about personal responsibility, which lead people to make unhelpful interpretations of normally occurring intrusive thoughts. In other words, a “normal” intrusive thought becomes a clinical obsession when an individual interprets the occurrence or content of the intrusion as a sign of personal responsibility for causing or preventing harm to oneself or others. These misinterpretations result in a range of outcomes, including neutralising responses aimed at preventing harm from occurring (e.g., checking, washing, counting, etc.). Thus the theory suggests that misinterpretations of intrusive thoughts mediate the relationship between general beliefs and assumptions about personal responsibility (responsibility attitudes) and OC behaviour. While Salkovskis’ model has received a great deal of empirical and theoretical attention, to our knowledge this mediational pathway has not been empirically tested. Another focus in the literature has been on the relationship between perfectionism and OC symptoms, demonstrated in both clinical (Antony, Purdon, Huta, & Swinson, 1998; Freeston et al., 1997; Frost & Steketee, 1997; Hewitt, Flett, Turnbull-Donovan, & Mikail, 1991) and non-clinical studies (Frost & Shows, 1993; Frost, Steketee, Cohn, & Griess, 1994; Gershuny & Sher, 1995; Rhéaume, Ladouceur, & Freeston, 2000). It has long been suggested that perfectionistic thinking contributes to specific types of obsessions and compulsions e.g., checking or washing until it feels “just right” and doubts about whether a task has been completed correctly (McFall & Wollersheim, 1979). In addition to investigating how the various risk factors proposed by the OCCWG (1997) predict OCD symptoms individually, researchers have started to investigate how variables such as responsibility and perfectionism might work together in producing OCD symptoms. Perfectionism has been shown to account for a significant proportion of variance in OC symptoms after controlling for responsibility (Rhéaume, Freeston, Dugas, Letarte, & Ladouceur, 1995; Rhéaume et al., 2000), and Bouchard, Rhéaume and Ladouceur (1999) have suggested that “high perfectionistic tendencies could predispose individuals to overestimate their personal responsibility for negative events” (p. 245). Therefore, it is possible that assumptions and general beliefs, not only regarding responsibility, but also perfectionistic beliefs, might lead people to make unhelpful interpretations of intrusive thoughts. For example, an individual who has perfectionistic ideals may interpret the mere occurrence of an unacceptable thought as evidence that they are imperfect (Rhéaume et al., 1995). Perfectionism is commonly defined and assessed as being multidimensional (Frost, Marten, Lahart, & Rosenblate, 1990; Hewitt & Flett, 1991). However, there has been some debate in recent years over the relevance of some of the dimensions assessed by the multidimensional perfectionism scales. Shafran, Cooper and Fairburn (2002) argue that several of the dimensions assessed by current measures of perfectionism assess constructs that are related to perfectionism, rather than the core construct of perfectionism per se. In a recent study, Tozzi et al. (2004) suggested that Concern over Mistakes (CM; measured by the Frost Multidimensional Perfectionism Scale, MPS-F) was one of the core features of perfectionism, and that other dimensions measured by the MPS-F (such as Doubts about Actions and Personal Standards) may serve as indicators of CM. Furthermore, CM is one of the dimensions most commonly associated with psychopathology, including OC symptoms (e.g., Antony et al., 1998), and a recent study that compared CM with Personal Standards found that only CM was a significant predictor of OC symptoms in a non-clinical population ( Suzuki, 2005). Therefore, for the purposes of the present study, perfectionism is defined and assessed more specifically as CM. The aim of the present study is three-fold. The first aim is to test whether the misinterpretation of intrusive thoughts, as measured by the Responsibility Interpretations Questionnaire (RIQ; Salkovskis et al., 2000), mediates the relationship between general responsibility beliefs as measured by the Responsibility Attitude Scale (RAS; Salkovskis et al., 2000) and OC symptoms as measured by the Maudsley Obsessional Compulsive Inventory (MOCI; Hodgson & Rachman, 1977). The second aim is to test whether misinterpretation of intrusive thoughts also mediates the relationship between perfectionism (CM) and OC symptoms. The third aim is to examine the relative contribution of responsibility and perfectionism in predicting misinterpretations of intrusive thoughts and OC symptoms when all variables are included in the model.