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.To conduct a meta-analytic and systematic review of the literature on the effectiveness of non-biological treatments for negative symptoms in psychotic disorders.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.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.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.

These results highlight the importance of achieving and maintaining remission of both negative and positive symptoms for longer periods in patients with a first episode of a psychotic disorder and the need for effective interventions to do so.

This study aimed to determine if, following two years of early intervention service for first-episode psychosis, three-year extension of that service was superior to three years of regular care. We conducted a randomized single blind clinical trial using an urn randomization balanced for gender and substance abuse. Participants were recruited from early intervention service clinics in Montreal. Patients (N5220), 18-35 years old, were randomized to an extension of early intervention service (EEIS; N5110) or to regular care (N5110). EEIS included case management, family intervention, cognitive behaviour therapy and crisis intervention, while regular care involved transfer to primary (community health and social services and family physicians) or secondary care (psychiatric outpatient clinics). Cumulative length of positive and negative symptom remission was the primary outcome measure. EEIS patients had a significantly longer mean length of remission of positive symptoms (92.5 vs. 63.6 weeks, t54.47, p<0.001), negative symptoms (73.4 vs. 59.6 weeks, t52.84, p50.005) and both positive and negative symptoms (66.5 vs. 56.7 weeks, t52.25, p50.03) compared to regular care patients. EEIS patients stayed in treatment longer than regular care patients (mean 131.7 vs. 105.3 weeks, t53.98, p<0.001 through contact with physicians; 134.8 6 37.7 vs. 89.8 6 55.2, t56.45, p<0.0001 through contact with other health care providers) and received more units of treatment (mean 74.9 vs. 39.9, t54.21, p<0.001 from physicians, and 57.3 vs. 28.2, t54.08, p<0.001 from other health care professionals). Length of treatment had an independent effect on the length of remission of positive symptoms (t52.62, p50.009), while number of units of treatment by any health care provider had an effect on length of remission of negative symptoms (t522.70, p50.008) as well as total symptoms (t522.40, p50.02). Post-hoc analysis showed that patients randomized to primary care, based on their better clinical profile at randomization, maintained their better outcome, especially as to remission of negative symptoms, at the end of the study. These data suggest that extending early intervention service for three additional years has a positive impact on length of remission of positive and negative symptoms compared to regular care. This may have policy implications for extending early intervention services beyond the current two years.