Background: Internet support groups (ISGs) are popular, particularly among people with depression, but there is little high quality evidence concerning their effectiveness. Aim: The study aimed to evaluate the efficacy of an ISG for reducing depressive symptoms among community members when used alone and in combination with an automated Internet-based psychotherapy training program. Method: Volunteers with elevated psychological distress were identified using a community-based screening postal survey. Participants were randomised to one of four 12-week conditions: depression Internet Support Group (ISG), automated depression Internet Training Program (ITP), combination of the two (ITP+ISG), or a control website with delayed access to e-couch at 6 months. Assessments were conducted at baseline, post-intervention, 6 and 12 months. Results: There was no change in depressive symptoms relative to control after 3 months of exposure to the ISG. However, both the ISG alone and the combined ISG+ITP group showed significantly greater reduction in depressive symptoms at 6 and 12 months follow-up than the control group. The ITP program was effective relative to control at post-intervention but not at 6 months. Conclusions: ISGs for depression are promising and warrant further empirical investigation. Trial Registration: Controlled-Trials.com <ext-link ext-link-type="uri" xlink:href="http://www.controlled-trials.com/ISRCTN65657330" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">ISRCTN65657330</ext-link>.