Understanding Anticipatory Anhedonia in Schizophrenia and Depression: Linking Reward Representation Maintenance from a Transdiagnostic Perspective

Background and hypothesis: Anticipatory anhedonia is common in both schizophrenia (SCZ) and major depressive disorder (MDD). Under the transdiagnostic framework of the Research Domain Criteria, this study investigated how reward representation maintenance relates to anticipatory pleasure in patients with SCZ and MDD. Study design: We recruited 61 SCZ patients, 60 MDD patients, and 77 age-matched healthy controls (HCs). All the participants completed the Reward Representation Maintenance Task, which was designed to measure the capacity of reward representation maintenance and anticipatory pleasure. Study results: Mixed-design analyses of covariance (ANCOVAs) revealed the significant group difference in mismatch rate (MR; F(2,194) = 14.24, P < .001, partial eta 2 = 0.130) while maintaining reward representation, with both SCZ (P < .001) and MDD (P < .001) patients exhibiting higher MR than HC group. When anticipating rewards, MDD patients showed fewer number of button press (NBR) than HC when facing large rewards (P < .001). SCZ patients slightly differed by showing a significant decrease in NBR for large rewards (P < .001) and an increase for small rewards (P = .006) compared to HC. Additionally, higher MR in both SCZ and MDD patients was significantly associated with a reduced level of NBR of large rewards. Conclusions: Our findings suggest that the common dysfunction in reward representation maintenance may contribute to the emergence of anticipatory anhedonia in SCZ and MDD patients, though there remains nuances. These insights advance our comprehension of the cognitive foundations of anticipatory anhedonia and lay the groundwork for a transdiagnostic approach to comprehend anhedonia effectively.