Nonpharmacological interventions for subthreshold depression in adults: A systematic review and network meta-analysis

•Compared with physical activity (PA) and psychosocial intervention, psychotherapy may be the most effective nonpharmacological intervention to improve subthreshold depression in adults.•Compared with internet-based cognitive behavioral therapy, PA and other nonpharmacological interventions, cognitive behavioral therapy (CBT) may be the most effective intervention to improve subthreshold depression in adults.•CBT can effectively improve the symptoms of subthreshold depression compared with the control groups, which provides us with a relevant reference for the selection of treatment methods for subthreshold depression in the future. Subthreshold depression (StD) is very common, with an estimated global incidence of 25%, and is associated with other clinical conditions. Nonpharmacological interventions have been demonstrated to be effective, but which one is best should be further investigated. This study aims to compare and rank the efficacy of nonpharmacological interventions in adults with StD. Ten databases were searched, and comparisons were made using a random-effects network meta-analysis using the frequentist framework. The assumption of local consistency was assessed by using the node-splitting method. The surface under the cumulative ranking curve (SUCRA) was used to separately rank each intervention. A total of 32 randomized controlled trials (RCTs) were included. The results showed that psychotherapy, as an intervention class, had significantly positive effects compared to control groups (SMD = -0.78, 95% CI: -1.06, -0.49) and had the highest rank (SUCRA, 79.0%; mean rank, 1.6). Cognitive behavioral therapy (CBT), as an individual intervention, had significantly positive effects relative to all control groups and had the highest rank (SUCRA, 82.5%; mean rank, 3.1). We speculate that psychotherapy, especially CBT, may be the most effective nonpharmacological intervention to improve StD in adults. More RCTs examining the efficacy of different nonpharmacological interventions are needed.