Decision-making of patients with major depressive disorder in the framework of action control.

Introduction: Patients with major depressive disorder (MDD) experience dysfunctional emotional states and cognitive impairments, leading to behavioural, social, and functional issues. Neurocognitive theory proposes that the initiation and maintenance of MDD is primarily the result of a deficit of action control which in turn would lead to decision-making impairments. Methods: We assessed 27 medicated outpatients with MDD who were demographically matched with 16 healthy participants on decision-making (DM) processes (Iowa Gambling Task (IGT) and Reversal Learning Task (RLT)), clinical variables (depressive symptoms and self-efficacy), and volition (Lille Apathy Rating Scale). Results: Patients with MDD displayed deficits on the IGT but not on the RLT. Correlational analysis of patients with MDD revealed no significant associations between IGT or RLT performance and volition, depressive symptom severity, and self-efficacy. However, differences on the IGT between patients with MDD and controls became non-significant when controlling for the variance of these scores. Conclusions: MDD appears to have an impact on dynamic DM processes, while basic processes are preserved. Limitations as well as directions for future research are discussed with regard to the neurocognitive model of depression.