IntroductionMusic therapy (MT) is a complementary creative arts treatment aimed at maintaining, restoring, and furthering physical, emotional, and mental health. This systematic review aimed to assess the effectiveness of MT for the treatment of autism spectrum disorder, dementia, depression, insomnia, and schizophrenia. In addition, the MT methods used for these indications were analyzed.MethodsFor this update of five Cochrane reviews, four databases (Medline, Embase, The Cochrane Library, and PsycINFO) were systematically searched for studies published from 2013 to 2020. Two review authors independently performed the study selection and data extraction. The methodological quality of the included trials was assessed using the Risk of Bias in Non-randomised Studies - of Interventions (ROBINS-I) tool and the Cochrane Risk of Bias tool for randomized controlled trials.ResultsTen RCTs (1,248 patients) met the inclusion criteria. For schizophrenia, no study could be included. MT improved the following: behavior, social communication, and the parent-child relationship in patients with autism; mood for patients with depression; and sleep quality for patients with insomnia. In patients with dementia, MT enhanced mood, behavior (severe disease stage), and cognitive function, whereas cognition was unchanged. Memory was improved only in the mild disease stage. None of the studies observed any significant long-term effects of MT in these patient groups. Both active (playing music) and receptive (listening to music) methods were used for dementia, whereas active methods were applied for autism spectrum disorder and depression. For insomnia, only receptive methods were used.ConclusionsThe findings of this update of reviews provides evidence that MT may help patients diagnosed with an autism spectrum disorder, dementia, depression, insomnia, or schizophrenia. It is crucial to focus on patient-related evidence-based health care. MT improves physical, psychological, and social aspects, but more research investigating the long-term effects of MT in these patient groups is needed as it is crucial to know how long the effects of MT last.