Effectiveness of a Web-Based Guided Self-help Intervention for Outpatients With a Depressive Disorder: Short-term Results From a Randomized Controlled Trial.

BACKGROUND: Research has convincingly demonstrated that symptoms of depression can be reduced through guided Internet-based interventions. However, most of those studies recruited people form the general population. There is insufficient evidence for the effectiveness when delivered in routine clinical practice in outpatient clinics.

OBJECTIVE: The objective of this randomized controlled trial was to study patients with a depressive disorder (as defined by the Diagnostic and Statistical Manual of Disorders, fourth edition), as assessed by trained interviewers with the Composite International Diagnostic Interview, who registered for treatment at an outpatient mental health clinic. We aimed to examine the effectiveness of guided Internet-based self-help before starting face-to-face treatment.

METHODS: We recruited 269 outpatients, aged between 18 and 79 years, from outpatient clinics and randomly allocated them to Internet-based problem solving therapy (n=136), with weekly student support, or to a control condition, who remained on the waitlist with a self-help booklet (control group; n=133). Participants in both conditions were allowed to take up face-to-face treatment at the outpatient clinics afterward. We measured the primary outcome, depressive symptoms, by Center for Epidemiological Studies Depression scale (CES-D). Secondary outcome measures were the Hospital Anxiety and Depression Scale Anxiety subscale (HADS-A), Insomnia Severity Index questionnaire (ISI), and EuroQol visual analog scale (EQ-5D VAS). All outcomes were assessed by telephone at posttest (8 weeks after baseline).

RESULTS: Posttest measures were completed by 184 (68.4%) participants. We found a moderate to large within-group effect size for both the intervention (d=0.75) and the control (d=0.69) group. However, the between-group effect size was very small (d=0.07), and regression analysis on posttreatment CES-D scores revealed no significant differences between the groups (b=1.134, 95% CI -2.495 to 4.763). The per-protocol analysis (≥4 sessions completed) results were also not significant (b=1.154, 95% CI -1.978 to 7.637). Between-group differences were small and not significant for all secondary outcomes. Adherence to the intervention was low. Only 36% (49/136) received an adequate dosage of the intervention (≥4 of 5 sessions). The overall treatment satisfaction was moderate.

CONCLUSIONS: Internet-based problem solving therapy is not more effective in reducing symptoms of depression than receiving an unguided self-help book during the waitlist period at outpatient mental health clinics. The effect sizes are much smaller than those found in earlier research in the general population, and the low rates of adherence indicate that the acceptability of the intervention at this stage of treatment for depressed outpatients is low. However, taking into account that there is much evidence for the efficacy of Internet-based treatments, it is too early to draw firm conclusions about the effectiveness of these treatments in outpatient clinics as a whole.

TRIAL REGISTRATION: Netherlands Trial Register NTR2824; https://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2824 (Archived by WebCite at https://www.webcitation/ 6g3WEuiqH).