Negative symptoms and everyday functioning in schizophrenia: a cross-sectional study in a real world-setting

Negative symptoms have been suggested to have a greater impact on real-world functioning in schizophrenia than other symptoms. We aimed to examine the relationship of specific negative symptoms components ("expressive deficits" - DE - which include alogia and blunted affect, and "avolition" - AA - which includes amotivation, anhedonia, and asociality), with separate domains of real-world outcomes (the Personal and Social Performance Scale - PSP - and selected items of the Heinrichs Quality of Life Scale - QLS - that did not overlap with negative symptoms) and two functional milestones (recent employment and marriage). Regression analyses were performed to identify the determinants of QLS and PSP scores and of the two milestones, in 92 consecutive outpatients with stable schizophrenia. AA was the strongest predictor of QLS interpersonal relations and social network (IRSN), PSP total score and the first three PSP domains. The variance explained ranged from 36% for PSP self care to 54% for the PSP personal and social relationships. Moreover, higher scores in AA were significant predictors of the single status. DE does not appear to have an impact at real-world functional performance. Taken together, our analysis indicates a relatively specific set of relationships between the AA subdomain and aspects of real-world functioning in schizophrenia. These findings, if confirmed, could have important implications for research, diagnostics and treatment: in fact our results would suggest that AA and DE should be analyzed as separate and distinct domains to be rated and treated individually.