Reinforcement learning is positively associated with anhedonia symptoms

Impairments in reward-related behavior are characteristic of major depressive disorder and closely linked with anhedonia. While previous research has suggested a negative relationship between reward-related behavior and symptoms of depression or anhedonia, findings across clinical and non-clinical studies are mixed. To investigate this relationship, we conducted three online studies with a combined sample of over 600 participants. Participants completed reinforcement learning tasks which involved the selection of either the more rewarding response or more rewarding stimulus. Contrary to expectations, we consistently observed a positive association between reinforcement learning performance and anhedonia symptoms across all studies: an exploratory study, a preregistered replication, and an independent dataset utilizing a different learning task. Depression symptoms overall showed only weak positive associations with performance. Our results contrast with the assumption of a negative association between reward-related task behavior and symptoms of depression or anhedonia. Instead, our findings in large non-selective samples suggest that anhedonia symptoms can be positively associated with reward-guided behavior.