Diagnostic differences in social anhedonia: A longitudinal study of schizophrenia and major depressive disorder

This study examined the hypothesis that, in schizophrenia, elevated trait s ocial anhedonia (SA) is a stable individual difference, whereas in depressi on, increased SA is a reflection of a current clinical state that will dimi nish with recovery. Differences in trait Negative Affect (NA) and Positive Affect (PA) were also examined. Individuals with schizophrenia (n = 55) and depression (n = 34) were evaluated at baseline during hospitalization and compared with nonpsychiatric control participants (n = 41). Participants we re assessed again at a 1-year follow-up. At baseline, compared with control participants, individuals with schizophrenia and depression were both char acterized by elevated SA, greater NA, and lower PA. In schizophrenic indivi duals, elevated SA remained stable over the follow-up. However, in recovere d depressed patients, SA declined over the follow-up period. Group differen ces remained in NA and PA over the 1-year follow-up. These results support the view that elevated SA is enduring in schizophrenia but that elevated SA is transiently related to clinical status in depression.