اعتبار پیش بینی شده از ایده های مقیاس بالاتر از حد ارزشگذاری: نتیجه در اختلالات بدریخت انگاری و وسواس

Overvalued ideas have been theoretically implicated in treatment failure for obsessive–compulsive disorder (OCD). Until recently, there have not been valid assessments for determining severity of overvalued ideas. One recent scale, the Overvalued Ideas Scale (OVIS; Neziroglu, McKay, Yaryura-Tobias, Stevens & Todaro, 1999, Behaviour Research and Therapy, 37, 881–902) has been found to validly measure overvalued ideas. However, its predictive utility has not been determined. Two studies were conducted to examine the extent to which the OVIS predicts treatment response. Study 1 examined the response to behavioral therapy in a group of participants diagnosed with OCD. Residual gain scores showed a significant correlation between treatment outcome for compulsions and pretreatment OVIS scores (28.1% variance accounted). Pretreatment OVIS scores were not significantly correlated with residual gains in obsessions (1.7% variance accounted). The predictive utility of the OVIS was superior to a single item assessment of overvalued ideas available on the Yale–Brown Obsessive Scale in predicting outcome for compulsions. For this item, the variance accounted for compulsions was 6.3% and for obsessions was 3.9%. Study 2 examined the response to behavioral therapy in a group of participants diagnosed with body dysmorphic disorder (BDD), a condition ostensibly linked to OCD and presumed to present with higher levels of overvalued ideas. Residual gains scores showed a significant relationship between obsessions and OVIS (accounting for 34.8% of the variance), but not for compulsions (10.2% variance accounted). As in Study 1, the predictive utility of the OVIS was superior to the single item assessment (with 0.2% variance accounted for compulsions, 2.4% variance accounted for obsessions). Taken together, the studies reported here show that this OVIS is predictive of treatment outcome, and the predictive value depends on which symptoms are used to assess outcome. Further, the scale is more effective in predicting outcome than a widely used single item assessment.

Obsessive–compulsive disorder (OCD) is a major psychiatric condition affecting approximately 2.5% of the general population (Reiger, Boyd & Burke, 1988). Although the theories guiding the etiology and maintenance of the condition have changed over time, the descriptive psychopathology has remained essentially unchanged (LeGrand du Salle, 1875 and Westphal, 1878). The major symptoms include obsessions (intrusive and unwanted thoughts) and compulsions (repetitive behaviors typically aimed at alleviating the obsessions), as well as doubting. Secondary symptoms such as depression, anxiety, and social or occupation dysfunction often accompany OCD. Typically, the primary symptoms as viewed by patients with OCD are senseless yet uncontrollable. In an effort to identify prognostic variables that predict treatment outcome, it has been concluded that individuals with OCD who view their symptoms as sensible and reasonable are likely to have poorer treatment response (Kozak & Foa, 1994). The most recent revision to the Diagnostic and Statistical Manual (DSM-IV; American Psychiatric Association, 1994) has added the identifier ‘with poor insight’ for diagnoses of OCD. This is intended to denote persons with OCD who view their symptoms as reasonable. In the research literature on OCD, this has been termed overvalued ideation ( Foa, 1979 and Kozak and Foa, 1994). It is important to distinguish insight from overvalued ideas, as the two connote different psychological phenomena. In the case of insight, this is a term describing a gradation of personal awareness into one’s disorder as giving rise to disorder specific beliefs. Overvalued ideas, on the other hand, refer more to an idea or belief regarding the sensibility of one’s pattern of thinking. There have been different positions adopted regarding the relation between overvalued ideas and psychopathology. For example, Wernicke (1906) determined that overvalued ideas were the source of attention disturbance and impaired judgement. Jaspers (1913) on the other hand, felt that overvalued ideas were associated with righteousness or behaviors that had societal gain at personal cost. Kozak and Foa (1994) more recently suggested overvalued ideas lie on a continuum between rational thoughts and delusions, with fluctuations along this continuum over time. Although theoretically linked to poorer treatment outcome ( Basoglu et al., 1988 and Lelliott et al., 1988), and identified in individual and small group case analyses ( Insel & Akiskal, 1986), assessment tools for quantifying overvalued ideas have been few, and with undetermined psychometric properties. Most assessments of overvalued ideas have been single item assessments (as in the Yale–Brown Obsessive Compulsive Scale; Goodman et al., 1989), dichotomous ratings based on clinical criteria but without established psychometric properties ( Foa et al., 1995), and a scale that assesses delusions in a variety of distinct disorders ( Eisen et al., 1998). Either because the scales have not established reliability and validity or because they do not specifically measure overvalued ideas, the Overvalued Ideas Scale (OVIS) was developed ( Neziroglu, McKay, Yaryura-Tobias, Stevens & Todaro, 1999). Although the OVIS has been shown to have acceptable test–retest and interrater reliability, and acceptable convergent validity with measures of OCD and psychotic experiences, there has not yet been a determination of whether and how well this scale predicts treatment outcome. It was hypothesized that the OVIS would show better predictive validity than a single item assessment of overvalued ideas (item 11 from the Y–BOCS) in a sample of patients diagnosed with OCD. Although the OVIS effectively predicted treatment outcome for compulsion in a group diagnosed with primary OCD, the test that remains is determining the effectiveness of the OVIS in predicting treatment outcome in a group theoretically related to OCD. The utility of overvalued ideas in predicting treatment outcome is not restricted to OCD, but could reasonably be applied to other conditions theoretically related to OCD. These conditions are collectively referred to as the obsessive–compulsive spectrum. As yet, few conditions have received extensive empirical support for inclusion in this spectrum. Instead, there have been various levels of mixed support for some of the proposed spectrum disorders. One condition, however, has received considerable attention and may plausibly be included in the spectrum. This condition, Body Dysmorphic Disorder (BDD), has shown comparative features to OCD based on the following psychopathological elements: (1) symptom presentation (Phillips et al., 1993, Hollander and Phillips, 1993, McKay et al., 1997 and Phillips et al., 1998); (2) response to behavioral interventions such as exposure with response prevention (Marks and Mishan, 1988, Watts, 1990, Neziroglu and Yaryura-Tobias, 1993a, Neziroglu and Yaryura-Tobias, 1993b, Rosen, 1995, Veale et al., 1996, McKay et al., 1997 and Wilhelm et al., 1999; McKay, 1999); and (3) response to medication (Neziroglu et al., 1999, Neziroglu and Yaryura-Tobias, 1997, Hollander et al., 1989 and Neziroglu and Yaryura-Tobias, 1993b; Jenike, 1984). BDD is characterized by repetitive thoughts about one’s appearance (usually in the form of a perceived defect), and compulsive behaviors designed to reduce the perception that others will notice the perceived defect. Noteworthy in the diagnosis of BDD is that there be no evidence of eating disorders — that is, body shape disturbance as is common in eating disorders. BDD is typified by more focused concerns. Some common bodily concerns among BDD sufferers are perceptions of defects in the nose, forehead, legs, genitals, or feet (Neziroglu and Yaryura-Tobias, 1993a and Neziroglu and Yaryura-Tobias, 1993b). Recent research (Eisen, Phillips, Rasmussen & Luce, 1997; McKay et al., 1997) has suggested that one characteristic distinguishing BDD from OCD is the level of overvalued ideas. It is far more common for BDD sufferers to believe that their bodily concerns are realistic. McKay et al. (1997) showed that, in comparison to a group with OCD, BDD patients had higher levels of overvalued ideas, but were essentially similar for measures of obsessions and compulsions. This single characteristic may set the tone for more difficult treatment, given the theoretical importance placed upon overvalued ideas in the treatment of OCD (Foa, 1979 and Kozak and Foa, 1994). Accordingly, BDD would be theoretically more difficult to treat although this has not been borne out in a few treatment outcome studies using cognitive behavioral therapy (Neziroglu et al., 2000, Neziroglu et al., 1996 and Neziroglu and Yaryura-Tobias, 1997; Rosen, Reiter & Orasan, 1995; Neziroglu and Yaryura-Tobias, 1993a and Neziroglu and Yaryura-Tobias, 1993b). However, some of these studies were limited in the number of patients who participated, they were not controlled studies, they did not use valid measurements of overvalued ideas and the patients were of questionable BDD diagnosis. For this reason it would not be fair to assume that overvalued ideas do not play a role in predicting treatment outcome in BDD patients. Since it appears from previous research that pretreatment overvalued ideas predict treatment outcome, the first study reported is an investigation of the predictive power of the OVIS on treatment outcome using the Y–BOCS in a group with OCD. By way of comparison, item 11 of the Y–BOCS was also examined for its predictive power with the treatment outcome measures. Study 2 is intended to examine how overvalued ideas are associated with treatment outcome in a group that is theoretically related, and has typically higher overvalued ideas, specifically BDD.