Reward-related decision-making in pediatric major depressive disorder: an fMRI study

Background: Although reward processing is considered an important part of affective functioning, few studies have investigated reward-related decisions or responses in young people with affective disorders. Depression is postulated to involve decreased activity in reward-related affective systems. Methods: Using functional magnetic resonance imaging (fMRI), we examined behavioral and neural responses to reward in young people with depressive disorders using a reward decision-making task. The task involved choices about possible rewards involving varying magnitude and probability of reward. The study design allowed the separation of decision/anticipation and outcome phases of reward processing. Participants were 9-17 years old and had diagnoses of major depressive disorder (MDD), anxiety disorders, or no history of psychiatric disorder. Results: Participants with MDD exhibited less neural response than control participants in reward-related brain areas during both phases of the task. Group differences did not appear to be a function of anxiety. Depressive and anxiety symptoms were associated with activation in reward-related brain areas. Conclusions: Results suggest that depression involves altered reward processing and underscore the need for further investigation of relations among development, affective disorders, and reward processing.