استدلال احتمالاتی در بیماران مبتلا به اختلال بدریخت انگاری

Background and Objectives Many patients with body dysmorphic disorder (BDD) have poor insight into their condition. Indeed, their conviction in their ugliness is often delusional. Perhaps the most robust information-processing abnormality associated with delusions is a jumping to conclusions (JTC) reasoning bias such that delusional individuals request significantly less information before making a decision relative to healthy controls. We investigated whether patients with BDD (n = 20) demonstrate a JTC reasoning style relative to patients with OCD (n = 20) and healthy controls (n = 20). Methods Participants completed a clinician-rated measure of delusionality and two tests of probabilistic reasoning: the beads task and the survey task. Results Patients with BDD did exhibit higher delusionality than the patients with OCD. They did not, however, exhibit a JTC reasoning bias relative to the patients with OCD or the healthy controls. Patients with poor insight BDD requested significantly less information before making a decision than did patients with fair insight BDD. Limitations The clinical groups were characterized by multiple comorbidities and concomitant medications. The BDD group had relatively good insight as compared to other studies examining delusionality in BDD. Conclusions Taken together, our results suggest that although a JTC reasoning bias was not present in all patients with BDD, a modest JTC reasoning bias may be present among patients with poor insight BDD. Future studies could provide additional information on this hypothesis. Highlights ►BDD patients exhibited higher focal delusionality than OCD patients. ►They did not request less information than OCD patients or healthy controls. ►Poor insight BDD patients requested less information than fair insight BDD patients. ►A JTC reasoning bias may be present among individuals with poor insight BDD. ►Future studies could provide additional information on this hypothesis.

Body Dysmorphic Disorder (BDD) is characterized by a preoccupation with imagined or slight defects in physical appearance (American Psychiatric Association, 2000). The preoccupation can be about any area of the body, but most frequently concerns the skin, hair, and nose (Phillips, Menard, Fay, & Weisberg, 2005). Individuals with BDD are often overwhelmed by intrusive and persistent thoughts and images related to their physical appearance. They also frequently perform ritualistic behaviors such as excessive grooming, mirror checking, applying makeup, or camouflaging their appearance with clothing or jewelry. BDD often causes marked social, educational, and occupational impairment. Sufferers may experience difficulty remaining in school, retaining jobs, or developing relationships as a result of their appearance concerns. For example, a study of 200 individuals with BDD revealed that 36% had missed at least one week of work in the prior month because of these concerns, and 11% had terminated their schooling because of BDD (Phillips et al., 2005). More than 25% reported attempting suicide at some point in their lives. Many individuals with BDD also have very poor insight into their disorder (Phillips, 2004 and Phillips et al., 1994). They often do not recognize that they suffer from a mental disorder. Rather, they consider their problem to be cosmetic. For example, in one study, 52 of 100 individuals with BDD said that for a significant period of time during the course of their disorder they were convinced of their ugliness (Phillips et al., 1994). Another study of 129 patients with BDD revealed that 84% (n = 108) were either delusional (n = 68) or had poor insight (n = 40) into their primary disorder-related belief (e.g., “I am ugly”; Phillips, 2004). Higher levels of delusionality among BDD patients are associated with less educational attainment, poorer social functioning, greater symptom severity, increased likelihood of drug abuse or dependence, and greater frequency of suicide attempts (Phillips, Menard, Pagano, Fay, & Stout, 2006). Thus, a better understanding of the factors that may contribute to this feature of BDD could significantly contribute to our understanding of the disorder and inform our treatment approaches. Researchers have begun investigating the cognitive processes that may contribute to the development and maintenance of BDD. Biases in interpretation (Buhlmann, Wilhelm et al., 2002), attention (Buhlmann, McNally, Wilhelm, & Florin, 2002), visual processing (Feusner et al., 2010 and Feusner et al., 2007), emotion recognition (Buhlmann, Etcoff, & Wilhelm, 2006) and memory (Deckersbach et al., 2000) have emerged. However, none of these abnormalities appear to explain the delusional features of the disorder. In the present study, we sought to examine whether individuals with BDD might exhibit cognitive biases that have been linked to delusion formation in other disorders.