This study aimed to investigate whether deficits in decision making were potential
endophenotype markers for OCD considering different phases of the disease.
Fifty-seven non-medicated OCD patients (nmOCD), 77 medicated OCD patients (mOCD), 48
remitted patients with OCD (rOCD) and 115 healthy controls were assessed with the
Iowa Gambling Task (IGT), which measured decision making under ambiguity, and the
Game of Dice Task (GDT), which measured decision making under risk. While the three
patients groups showed impaired performance on the IGT compared with healthy
controls, all patients showed intact performance on the GDT. Furthermore, the rOCD
patients showed a preference for deck B, indicating that they showed more
sensitivity to the frequency of loss than to the magnitude of loss, whereas the mOCD
patients showed a preference for deck A, indicating that they had more sensitivity
to the magnitude of loss than to the frequency of loss. These data suggested that
OCD patients had trait-related impairments in decision making under ambiguity but
not under risk, and that dissociation of decision making under ambiguity and under
risk is an appropriate potential neurocognitive endophenotype for OCD. The subtle
but meaningful differences in decision making performance between the OCD groups
require further study.