Background

Efficacy of guided Internet-based cognitive behaviour therapy (ICBT) for depression has been demonstrated in several randomised controlled trials. Knowledge on the effectiveness of the treatment, i.e. how it works when delivered within routine care, is however scarce. The aim of this study was to investigate the effectiveness of ICBT for depression.

Methods

We conducted a cohort study investigating all patients (N=1203) who had received guided ICBT for depression between 2007 and 2013 in a routine care setting at an outpatient psychiatric clinic providing Internet-based treatment. The primary outcome measure was the Montgomery Åsberg Depression Rating Scale-Self rated (MADRS-S).

Results

Patients made large improvements from pre-treatment assessments to post-treatment on the primary outcome (effect size d on the MADRS-S=1.27, 99% CI, 1.14–1.39). Participants were significantly improved in terms of suicidal ideation and sleep difficulties. Improvements were sustained at 6-month follow-up.

Limitations

Attrition was rather large at 6-month follow-up. However, additional data was collected through telephone interviews with dropouts and advanced statistical models indicated that missing data did not bias the findings.

Conclusions

ICBT for depression can be highly effective when delivered within the context of routine psychiatric care. This study suggests that the effect sizes are at least as high when the treatment is delivered in routine psychiatric care by qualified staff as when delivered in a controlled trial setting.