Stability and relationships between trait or state anhedonia and schizophrenic symptoms in schizophrenia: a 13-year follow-up study.Psychiatry Res. 2009 Apr 30; 166(2-3):132-40.PR
The aim of the present study was to explore the stability of anhedonia and its relationships with schizophrenic symptoms across a 13-year study period. We tested the hypothesis that trait anhedonia, rated by the Physical Anhedonia Scale (PAS), was stable and independent of schizophrenic symptoms across this period, while measures of state anhedonia were not. Sixty schizophrenic subjects were evaluated at two time points, at hospital admission or during an ambulatory psychiatric consultation and 13 years later. Trait anhedonia was assessed using the Chapman Physical Anhedonia Scale, while state anhedonia was assessed with a subscale extracted from the Beck Depression Inventory. The Positive and Negative Syndrome Scale (PANSS) was used to rate schizophrenic symptomatology. Unlike trait anhedonia, state anhedonia decreased significantly over time. Based on results from multiple regressions, negative and depressive dimensions were significant predictors of state anhedonia. Trait anhedonia was not associated with negative symptoms, but was associated with severity of disorganization symptoms at baseline and with our state measure of anhedonia at follow-up. In the current study, state and trait anhedonia were correlated, but depressive symptoms in general were not associated with physical anhedonia. The results indicated that trait anhedonia, in contrast to state anhedonia, had absolute stability, was independent of the negative dimension, as measured by the PANSS, of schizophrenic symptomatology and correlated with specific aspects of depressive anhedonia.