Dissociation of decisions in ambiguous and risky situations in obsessive-compulsive disorder.

Patients with obsessive-compulsive disorder (OCD) often show deficits in everyday decision-making, a phenomenon which is leading to a growing research interest in neuropsychological aspects of decision-making in OCD. Previous investigations of OCD patients demonstrated deficits in the Iowa Gambling Task (IGT), a decision-making task with implicit rules. Results were interpreted as reflecting orbitofrontal cortex dysfunctions observed in OCD. The aim of the present study is to investigate OCD patients' performance on the Game of Dice Task (GDT), a decision-making task with explicit and stable rules. For this purpose, 23 patients with OCD and 22 healthy comparison subjects were examined with the GDT and the IGT as well as with tests of executive functioning. While patients performed worse than comparison subjects on the IGT, they were unimpaired on the GDT and executive functioning tasks. Results further emphasize dysfunctions of the orbitofrontal cortex, but indicate intact functioning of the dorsolateral prefrontal cortex in patients with OCD.