Internet- and mobile-based depression interventions for people with diagnosed depression: A systematic review and meta-analysis

Background To summarize and critically evaluate the effectiveness of internet- and mobile-based interventions (IMIs) for depression in adults with a diagnosed depression. Methods Preregistered systematic review of RCTs investigating internet- and mobile-based interventions (IMIs) targeting adults with diagnosed depression. IMIs had to be compared with waitlist, attention placebo, other IMIs or other (face-to-face) therapies. A comprehensive search of primary studies was conducted. Study selection and data extraction was done by two independent researchers. Primary outcome was symptom severity of depression. Furthermore, treatment response, depression remission, treatment adherence, anxiety and quality of life were investigated. Random-effects meta-analyses were conducted where possible, as well as pre-planned subgroup and sensitivity analyses. Results Database search resulted in 4858 references, of which 19 studies were eligible for inclusion and provided data on 29 IMIs. IMIs showed beneficial effects on depression severity when compared to waitlist conditions at the end of treatment (pooled standardized mean difference (SMD) g = −0.90, 95% CI −1.07 to −0.73, n = 10). The comparison between different IMIs did not result in any superiority or inferiority. All IMIs reduced depression symptoms from pre- to post-treatment (within group SMD range −2.24; −0.64, n = 29) and from pre-treatment to follow-up assessments (SMD range −3.07; −0.93, n = 27). Conclusion IMIs significantly reduce depression symptoms in adults with diagnosed depression at the end of treatment and at follow-up assessments when compared to waitlist conditions. These findings argue for IMIs to be recommended in depression treatment guidelines.