Alterations in reward-related decision making in boys with recent and future depression

Background: Altered reward processing is postulated to be a feature of depression. Reward processing may be valuable to understanding early-onset depressive disorders, which tend to be chronic and recurrent. Methods: Reward-related decision making was examined within a longitudinal study of 221 11-year-old boys, 25 of whom had a depressive disorder at age 10 or 11. Participants completed a behavioral decision-making task involving varying probability and magnitude of obtaining reward. Results: Under conditions involving a high probability of winning, boys with depression failed to distinguish between options involving small or large possible reward. Boys with anxiety or externalizing disorders at age 10 or I I did not differ from others in their reward-related decisions. Low frequency of choosing the high-probability, large reward option at age 11 predicted depressive disorders, anxiety disorders, and depressive symptoms 1 year later. Furthermore, reward-related decisions predicted later depressive or anxiety disorders even when adjusting for the continuity of such disorders and the presence of concurrent externalizing disorders. Conclusions: Findings are consistent with affective neuroscience models of altered reward processing and diminished positive affect in depression. This study represents a step toward elucidating the motivational and emotional aspects of early-onset depression.