Decision-making using the Iowa gambling test in unaffected first-degree relatives of obsessive-compulsive disorder: Comparison with healthy controls and patients with obsessive-compulsive disorder.

Decision-making has been suggested as an endophenotype candidate for obsessive-compulsive disorder (OCD). However, few studies have examined whether decision-making under ambiguity is an endophenotype of OCD. This study aimed to investigate decision-making under ambiguity, as assessed by the Iowa Gambling Task (IGT), in patients with OCD and unaffected first-degree relatives (UFDR). Forty-seven non-medicated, non-co-morbid patients with OCD, 30 UFDR, and 47 healthy controls (HC) were compared in terms of decision-making using the IGT. The correlation between obsessive-compulsive symptoms and IGT performance was also investigated. Patients with OCD and UFDR performed worse than HC on the IGT. No correlation was found between obsessive-compulsive symptoms and IGT performance. A deficit in decision-making under ambiguity may be a trait and an endophenotype candidate for OCD.