15 May 2019: The depressed decision-maker

Joseph Kable
Department of Psychology
University of Pennsylvania

Depression is characterized by obvious changes in decision-making that cause distress and impairment. Here I will discuss some of our recent work aimed at understanding the specificity and dimensionality of decisional impairments in depression. We tested a large group of participants diagnosed with Major Depressive Disorder (MDD, n = 64) and healthy controls (n=64) on a comprehensive battery of nine value-based decision-making tasks which yield ten distinct measures. MDD participants were worse at learning from rewards and punishments, had more pessimistic predictions about the future, and were less persistent; but showed no differences in time or risk preferences or social bargaining behavior. Performance on learning, expectation, and persistence tasks each loaded on unique dimensions in a factor analysis and accounted for unique variance in predicting depressed status. Computational modeling of reward and punishment learning further revealed evidence for both hyposensitivity to outcomes and reduced learning rates in MDD relative to healthy controls. Our results highlight several learning and decision making processes that are the impacted in MDD whose more detailed study could shed light on distinct dimensions of this heterogeneous disorder.