Inference-based therapy for body dysmorphic disorder.

Body dysmorphic disorder (BDD) is a debilitating disorder characterized by an excessive pre-occupation with an imagined or very slight defect in one's physical appearance. Despite the overall success of cognitive behavioural therapy (CBT) in treating BDD, some people do not seem to benefit as much from this approach. Those with high overvalued ideation (OVI), for instance, have been shown to not respond well with CBT. The purpose of this study was to evaluate the efficacy of an inference-based therapy (IBT) in treating BDD. IBT is a cognitive intervention that was first developed for obsessive-compulsive disorder with high OVI, but whose focus on beliefs can also apply to a BDD population. IBT conceptualizes BDD obsessions (e.g., 'I feel like my head is deformed') as idiosyncratic inferences arrived at through inductive reasoning processes. Such primary inferences represent the starting point of obsessional doubt and the treatment focuses on addressing the faulty inferences that maintain the doubt. Thirteen BDD participants, of whom 10 completed, underwent a 20-week IBT for BDD. The participants improved significantly over the course of therapy, with large diminutions in BDD and depressive symptoms. OVI also decreased throughout therapy and was not found to be related to reduction in BDD symptoms. Although a controlled-trial comparing CBT with IBT is needed, it is proposed that IBT constitutes a promising treatment alternative for BDD especially in cases where OVI is high.