Abstract
BACKGROUND: Social anxiety disorder (SAD) substantially affects young individuals' social and academic functioning, emphasizing the need for accessible and effective treatments such as digital mental health interventions (DMHIs). OBJECTIVE: This systematic review and meta-analysis aimed to evaluate the efficacy of DMHIs for children, adolescents, and young adults with social anxiety symptoms. METHODS: For this systematic review and meta-analysis, we searched 6 electronic databases (PsycINFO, Embase, MEDLINE, PSYNDEX, PubMed, and Web of Science) for randomized controlled trials investigating DMHIs addressing social anxiety in young people (mean age <25 years). Two authors independently screened the records, extracted data, and assessed the risk of bias. For data analysis, a standardized effect size was calculated using Hedges g, along with 95% CIs, for each study. Meta-analyses were conducted using a random-effects model to account for heterogeneity. RESULTS: The systematic review included 22 studies, and the meta-analysis included 21 studies. The results significantly favored DMHIs (Hedges g=0.508, 95% CI 0.308-0.707; P<.001) over any control condition (ie, waitlist or active interventions) after the intervention, specifically those compared to waitlist control conditions (Hedges g=0.576, 95% CI 0.343-0.809; P<.001), those based on cognitive behavioral principles (Hedges g=0.610, 95% CI 0.361-0.859; P<.001), those incorporating SAD-specific components (Hedges g=0.878, 95% CI 0.469-1.278), and those delivered with human guidance (Hedges g=0.825, 95% CI 0.425-1.224; P<.001). Neither parental involvement nor age influenced outcomes significantly. When publication bias was considered, the overall effect remained significant (Hedges g=0.506, 95% CI 0.308-0.707). The risk-of-bias assessment indicated that most of the studies (16/22, 73%) showed some concerns; of the 22 studies, 3 (14%) were classified as high risk, and 3 (14%) were rated as low risk. The reporting of adherence varied substantially and could not be analyzed meta-analytically. CONCLUSIONS: The meta-analysis supports the efficacy of DMHIs for social anxiety compared to control conditions and the beneficial effects of guidance and interventions specifically designed for SAD. Furthermore, it highlights methodological shortcomings and heterogeneous reporting standards. Future research should prioritize higher methodological quality and should explore how effects are related to age and specific intervention components, including guidance and treatment modules. TRIAL REGISTRATION: PROSPERO CRD42023424181; https://www.crd.york.ac.uk/PROSPERO/view/CRD42023424181.