Depressive symptoms are associated with blunted reward learning in social contexts

Depression is characterized by a marked decrease in social interactions and blunted sensitivity to rewards. Surprisingly, despite the importance of social deficits in depression, non-social aspects have been disproportionally investigated. As a consequence, the cognitive mechanisms underlying atypical decision-making in social contexts in depression are poorly understood. In the present study, we investigate whether deficits in reward processing interact with the social context and how this interaction is affected by self-reported depression and anxiety symptoms in the general population. Two cohorts of subjects (discovery and replication sample: N = 50 each) took part in an experiment involving reward learning in contexts with different levels of social information (absent, partial and complete). Behavioral analyses revealed a specific detrimental effect of depressive symptoms–but not anxiety–on behavioral performance in the presence of social information, i.e. when participants were informed about the choices of another player. Model-based analyses further characterized the computational nature of this deficit as a negative audience effect, rather than a deficit in the way others’ choices and rewards are integrated in decision making. To conclude, our results shed light on the cognitive and computational mechanisms underlying the interaction between social cognition, reward learning and decision-making in depressive disorders.Author summary: Blunted sensitivity to rewards is at the core of depression. However, studies that investigated the influence of depression on decision-making have often done so in asocial contexts, thereby providing only partial insights into the way depressive disorders impact the underlying cognitive processes. Indeed, atypical social functioning is also a central characteristic of depression. Here, we aimed at integrating the social component of depressive disorders into the study of decision-making in depression. To do so, we measured the influence of self-reported depressive symptoms on social learning in participants performing an online experiment. Our study shows that depressive symptoms are associated with decreased performance only when participants are informed about the actions of another player. Computational characterizations of this effect reveal that participants with more severe depressive symptoms differ only in the way they learn from their own actions in a social context. In other words, our results indicate that depressive symptoms are associated with a negative audience effect and thus provide new insights into the way social cognition and decision-making processes interact in depression.