The efficacy of online-delivered treatment for generalised anxiety disorder: a systematic review and meta-analysis

Generalized Anxiety Disorder (GAD) is typically considered a chronic condition characterised by excessive worry. Lifetime prevalence is 4.3-5.9%, yet a small percentage seek treatment. GAD can be treated and in recent years online-delivered treatment interventions have shown promise. The paper aimed to systematically search for literature on online-delivered psychological interventions for the treatment of GAD and conduct a meta-analysis to examine their efficacy. The purpose of the paper is to inform the community of researchers in internet delivered interventions of the current state of the art and research gaps that require attention. A systematic search of the literature was conducted to find all studies for online-delivered treatments for GAD (N=20). Using Review Manager 5 all Randomized Controlled trials (RCTs; n = 11) that met our established eligibility criteria were included into a meta-analysis that calculated effect sizes via the standardised mean difference. Compared to the waiting-list controls, the results demonstrate positive outcomes for GAD symptoms (d = -0.91) and its central construct of pathological worry (d = -0.74). The meta-analysis supports the efficacy of online-delivered treatments for GAD including the use of disorder-specific (4 studies) and transdiagnostic treatment protocols (7 studies) delivered online. Caution is advised regarding the results as the data is limited and highly heterogeneous, but revealing of what future research might be needed