Verbal memory impairments predict social connection via anhedonia: a transdiagnostic, population-based study

BackgroundAnhedonia and episodic memory impairments are transdiagnostic features of mental illness, robustly linked to functional outcomes across diagnostic boundaries. Episodic memory supports the ability to simulate future events, including reward. Impairments in these systems may therefore contribute to motivational and pleasure negative symptoms such as anhedonia. Prior work in our group highlighted negative symptoms, including anhedonia, as mediators of the relation between episodic verbal memory and functional outcomes in psychosis. The current study tested whether a similar pathway linking verbal episodic memory, anhedonia, and social connection is evident in a population-based transdiagnostic sample. MethodsParticipants (N=8,575) were drawn from the UK Biobank; the sample included adults with and without lifetime psychiatric diagnosis, matched on age, sex, and socioeconomic status. Verbal episodic memory was assessed with the Paired Associate Learning task, anhedonia with a self-report item indexing frequency of little interest/pleasure, and social connection through self-reported frequency of family and friend visits. Mediation analyses tested the indirect effects of verbal memory on social connection through anhedonia. Moderated mediation analyses tested whether this indirect effect differed by group (patients vs. controls), sex, or broad symptom dimensions (internalizing, externalizing, psychosis). An alternative model tested verbal memory as the mediator between anhedonia and social connection. ResultsAnhedonia significantly mediated the association between verbal memory and social connection, though the indirect effect was small (a × b = 0.0024, 95% CI [0.0012, 0.0036], p < 0.001). No statistically significant moderation was observed by group, sex, or symptom dimensions. The alternative mediation through verbal memory was not significant.ConclusionThese findings support a subtle population-level pathway linking episodic memory, anhedonia, and social connection across individuals with and without lifetime psychiatric diagnoses. Ultimately, highlighting anhedonia may act as a candidate symptom-level bridge between neurocognitive impairment and social disconnection within the multiscale architecture of dimensional psychopathology.