Psychological interventions for early-phase schizophrenia: protocol for a systematic review and network meta-analysis [version 1; peer review: 2 approved, 1 approved with reservations]

Introduction Treating the early phase of schizophrenia is crucial for preventing further episodes and improving quality of life, functioning, and social inclusion. Pharmacotherapies are first-line treatments, but have limitations. There is consensus on the need for non-pharmacological interventions for individuals in the early phase of schizophrenia. Several psychological interventions have shown promising effects; however, their comparative effectiveness remains largely unknown. To address this issue, a network meta-analysis will be performed. We aim to develop a hierarchy of existing psychological treatments concerning their efficacy and tolerability, which will inform treatment guidelines. Protocol Randomized controlled trials (RCTs) investigating psychological interventions for first-episode psychosis, first-episode schizophrenia, or early phase schizophrenia will be included. The primary outcome will be overall schizophrenia symptoms (measured up to 6 and 12 months, and at the longest follow-up) and relapse as a co-primary outcome. Secondary outcomes are premature discontinuation; change in positive, negative, and depressive symptoms of schizophrenia; response; quality of life; overall functioning; satisfaction with care; adherence; adverse events; and mortality. The study selection and data extraction are performed by two independent reviewers. We will assess the risk of bias of each study using the Cochrane Risk of Bias tool 2 and evaluate the confidence in the results using Confidence in Network Meta-Analysis (CINeMA). Subgroup and sensitivity analyses will be conducted to explore heterogeneity and assess the robustness of our findings. Discussion This systematic review and network meta-analysis aims to compare multiple existing psychological interventions, establishing which are best for symptom reduction, relapse prevention, and other important outcomes in early phase schizophrenia. Our results may provide practical guidance concerning the most effective psychological intervention to reduce symptom severity and the societal burden associated with the disorder.