Psychological and psychosocial interventions for negative symptoms in psychosis: systematic review and meta-analysis.

Background Negative symptoms observed in patients with psychotic disorders undermine quality of life and functioning. Antipsychotic medications have a limited impact. Psychological and psychosocial interventions, with medication, are recommended. However, evidence for the effectiveness of specific non-biological interventions warrants detailed examination. Aims To conduct a meta-analytic and systematic review of the literature on the effectiveness of non-biological treatments for negative symptoms in psychotic disorders. Method We searched for randomised controlled studies of psychological and psychosocial interventions in psychotic disorders that reported outcome on negative symptoms. Standardised mean differences (SMDs) in values of negative symptoms at the end of treatment were calculated across study domains as the main outcome measure. Results A total of 95 studies met our criteria and 72 had complete quantitative data. Compared with treatment as usual cognitive-behavioural therapy (pooled SMD -0.34, 95% CI -0.55 to -0.12), skills-based training (pooled SMD -0.44, 95% CI -0.77 to -0.10), exercise (pooled SMD -0.36, 95% CI -0.71 to -0.01), and music treatments (pooled SMD -0.58, 95% CI -0.82 to -0.33) provide significant benefit. Integrated treatment models are effective for early psychosis (SMD -0.38, 95% CI -0.53 to -0.22) as long as the patients remain in treatment. Overall quality of evidence was moderate with a high level of heterogeneity. Conclusions Specific psychological and psychosocial interventions have utility in ameliorating negative symptoms in psychosis and should be included in the treatment of negative symptoms. However, more effective treatments for negative symptoms need to be developed.