BackgroundThere are few published controlled trials examining the efficacy of Internet-based treatment for postnatal depression (PND) and none that assess diagnostic status (clinical remission) as the primary outcome. This is despite the need to improve treatment uptake and accessibility because fewer than 50% of postnatally depressed women seek help, even when identified as depressed.ObjectiveIn a randomized controlled trial (RCT), we aimed to test the efficacy of a 6-session Internet intervention (the MumMoodBooster program, previously evaluated in a feasibility trial) in a sample of postnatal women with a clinical diagnosis of depression. The MumMoodBooster program is a cognitive behavioral therapy (CBT) intervention, is highly interactive, includes a partner website, and was supported by low-intensity telephone coaching.MethodsThis was a parallel 2-group RCT (N=43) comparing the Internet CBT treatment (n=21) to treatment as usual (n=22). At baseline and at 12 weeks after enrollment, women’s diagnostic status was assessed by telephone with the Standardized Clinical Interview for DSM-IV (SCID-IV) and symptom severity with the Beck Depression Inventory (BDI-II). Depression symptoms were measured repeatedly throughout the study period with the Patient Health Questionnaire (PHQ-9).ResultsAt the end of the study, 79% (15/19) of women who received the Internet CBT treatment no longer met diagnostic criteria for depression on the SCID-IV (these outcome data were missing for 2 intervention participants). This contrasted with only 18% (4/22) remission in the treatment as usual condition. Depression scores on the BDI-II showed a large effect favoring the intervention group (d=.83, 95% CI 0.20-1.45). Small to medium effects were found on the PHQ-9 and on measures of anxiety and stress. Adherence to the program was very good with 86% (18/21) of users completing all sessions; satisfaction with the program was rated 3.1 out of 4 on average.ConclusionsOur results suggest that our Internet CBT program, MumMoodBooster, is an effective treatment option for women clinically diagnosed with PND. This is one of only two controlled evaluations of specialized online psychological treatment among women clinically diagnosed with PND. MumMoodBooster appears to be a feasible, effective treatment option, which is potentially accessible to large numbers of women in metropolitan, rural, and remote areas. Future work might be focused profitably on establishing comparability with face-to-face treatments and purely self-guided delivery. We have commenced a larger RCT comparing MumMoodBooster with face-to-face CBT.Trial RegistrationAustralian and New Zealand Clinical Trials Registry (ANZCTR): ACTRN12613000113752; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=363561 (Archived by WebCite® at http://www.webcitation.org/6f64kuyLf).