Psychiatric symptoms and quality of life in schizophrenia: a meta-analysis.

Quality of life (QoL) has been recognized as an important outcome of schizophrenia treatment, yet the determinants of QoL for individuals with schizophrenia are not well known. Research has consistently found psychiatric symptoms to be negatively related to QoL, however, findings concerning the strength of these relationships have been mixed, making it difficult to determine the degree to which such symptoms are related to poor QoL. This research presents a systematic meta-analysis of studies examining the relationship between psychiatric symptoms and QoL in schizophrenia, in an effort to elucidate the determinants of QoL for this population. A total of 56 studies were extracted from literature searches of relevant databases for empirical reports published between 1966 and 2005 examining the relationship between positive, negative, and/or general psychiatric symptoms and QoL. Weighted effect size analyses revealed small relationships between psychiatric symptoms and QoL, with general psychopathology showing the strongest negative associations across all QoL indicators. Moderator analyses indicated that variation in effect sizes could be accounted for by differing operationalizations of QoL, study design, sample, and participant treatment setting. In particular, positive and negative symptoms were more strongly related to poor QoL among studies of schizophrenia outpatients, whereas general psychopathology showed a consistent negative relationship with QoL across all study samples and treatment settings. Implications for future research and treatment development are discussed.