A Systematic Review and Meta-Analysis of the Effectiveness of Adherence Therapy and Its Treatment Duration in Patients with Schizophrenia Spectrum Disorders

BACKGROUND: Adherence therapy (AT) is an intervention for improving medication adherence of people with schizophrenia spectrum disorders, but no systematic reviews have yet summarized the effectiveness and minimum treatment duration of AT. We here aimed to systematically examine the effectiveness of AT in improving outcomes versus treatment as usual (TAU) and its minimum effective duration for people diagnosed with schizophrenia spectrum disorders. PATIENTS AND METHODS: Eligible randomized controlled trials were identified from four databases (Web of Science, PubMed, CINAHL and Cochrane Library) for the period 1 January 2006 to 1 January 2023. Of 1087 retrieved candidate studies, five studies with a total of 726 participants met the inclusion criteria. The search terms consisted of adherence therapy, compliance therapy, schizophrenia, schizoaffective disorder, schizophrenic disorder, medication adherence, and medication compliance (combined with OR and AND). Two investigators independently selected studies, extracted data, and conducted bias risk assessments. Random-effects models were used to analyze the pooled data. RESULTS: Meta-analysis of the five selected studies showed that AT had a significantly greater positive effects than TAU on psychiatric symptoms, but no significant effects on adherence behaviors and attitudes. CONCLUSION: The AT had limited effects in terms of improving the attitudes and behaviors of people with schizophrenia spectrum disorders with respect to medication adherence, but did improve patients’ psychiatric symptoms. The therapy should be performed by trained staff for maximum benefit, and the recommended duration of the intervention is 12 hours.