Anhedonia and altered reward responsiveness: Relations to psychosocial functioning.

Background: Anhedonia-a core symptom of Major Depressive Disorder-is associated with poorer clinical outcomes, lower quality of life, and disrupted reward processing. However, putative relationships among self-reported anhedonia, well-being and anhedonic phenotypes (specifically, reward learning) remain largely unexplored. The main goal of the current study was to fill this gap in a large online adult community sample (N = 478). Methods: To evaluate how different approaches to assessing anhedonia may capture these relationships, we administered the Probabilistic Reward Task (PRT) to probe reward learning and two clinical scales: the Snaith-Hamilton Pleasure Scale (SHAPS) and the Dimensional Anhedonia Rating Scale (DARS). In a first step, the SHAPS was administered to identify anhedonic vs. non-anhedonic individuals, who then performed an online PRT. Results: Both scales were significantly associated with lower self-reported quality of life (QoL), as measured by the Quality of Life Enjoyment and Satisfaction Questionnaire Short Form (QLESQ-SF), with the SHAPS showing a stronger relationship to both QoL and reward learning. Follow-up computational modeling indicated the anhedonic group showed a significantly higher level of uncertainty while completing the PRT compared to the non-anhedonic group. Moreover, trial-by-trial analyses revealed group differences in PRT response patterns, such that anhedonic individuals were less likely to incorrectly indicate that they had seen the more frequently rewarded "rich" stimulus on trials that actually presented the less frequently rewarded "lean" stimulus. Conclusions: Findings highlight the utility of combining subjective and behavioral measures to better understand the impact of anhedonia on daily functioning and reinforcement learning processes.