Ten new studies have been added to this update; 18 studies with a total 1215 participants are now included. These examined effects of music therapy over the short, medium, and long-term, with treatment dosage varying from seven to 240 sessions. Overall, most information is from studies at low or unclear risk of bias
A positive effect on global state was found for music therapy compared to standard care (medium term, 2 RCTs, n = 133, RR 0.38 95% confidence interval (CI) 0.24 to 0.59, low-quality evidence, number needed to treat for an additional beneficial outcome NNTB 2, 95% CI 2 to 4). No binary data were available for other outcomes. Medium-term continuous data identified good effects for music therapy on negative symptoms using the Scale for the Assessment of Negative Symptoms (3 RCTs, n = 177, SMD – 0.55 95% CI -0.87 to -0.24, low-quality evidence). General mental state endpoint scores on the Positive and Negative Symptoms Scale were better for music therapy (2 RCTs, n = 159, SMD -0.97 95% CI -1.31 to -0.63, low-quality evidence), as were average endpoint scores on the Brief Psychiatric Rating Scale (1 RCT, n = 70, SMD -1.25 95% CI -1.77 to -0.73, moderate-quality evidence). Medium-term average endpoint scores using the Global Assessment of Functioning showed no effect for music therapy on general functioning (2 RCTs, n = 118, SMD -0.19 CI -0.56 to 0.18, moderate-quality evidence). However, positive effects for music therapy were found for both social functioning (Social Disability Screening Schedule scores; 2 RCTs, n = 160, SMD -0.72 95% CI -1.04 to -0.40), and quality of life (General Well-Being Schedule scores: 1 RCT, n = 72, SMD 1.82 95% CI 1.27 to 2.38, moderate-quality evidence). There were no data available for adverse effects, service use, engagement with services, or cost.