Internet-delivered cognitive behavioral interventions to reduce elevated stress: A systematic review and meta-analysis

Background: Face-to-face cognitive behavioral therapy (CBT) is the most promising treatment to reduce stress, but access to CBT is limited. Internet-delivered CBT (ICBT) enables large-scale dissemination at low costs. Evidence suggests that ICBT can reduce stress in subclinical and mixed diagnostic samples, but less is known about the effect of ICBT in targeted samples suffering from elevated perceived stress or stress-related disorders. Objective: To investigate the efficacy of ICBT specifically aimed at reducing stress in adults with elevated perceived stress or stress-related disorders. Methods: We searched for randomized controlled trials comparing ICBT with a control group in PubMed, Web of Science, and PsycInfo between 2010 and 2021. A meta-analysis of 14 comparisons (total N = 1831) was performed, and Cohen's d was calculated to assess the difference between intervention and control groups at posttest for the primary outcome self-rated stress. Effects on secondary outcomes of anxiety and depression were also investigated. Results: The pooled mean effect size for self-rated stress at posttest was d = 0.78 [CI 95 % 0.66-0.90]. For anxiety and depression, the effects were d = 0.69 [95 % CI 0.52-0.86] and d = 0.65 [95 % CI 0.56-0.75] respectively. The heterogeneity of results between studies was overall low to moderate. Subgroup analyses were not conducted due to the limited number of studies eligible for inclusion. Conclusions: Results provide evidence of the efficacy of ICBT to reduce stress, anxiety, and depressive symptoms in adults suffering from elevated stress or stress-related disorders. Findings have important implications for the development of safe and evidence-based treatment guidelines in the face of a rapid digital expansion.