A randomised controlled trial comparing group interpersonal psychotherapy with treatment as usual among rural Ugandans meeting symptom and functional impairment criteria for DSM–IV major depressive disorder or sub-threshold disorder showed evidence of effectiveness immediately following the intervention.

To assess the long-term effectiveness of this therapy over a subsequent 6-month period.

A follow-up study of trial participants was conducted in which the primary outcomes were depression diagnosis, depressive symptoms and functional impairment.

At 6 months, participants receiving the group interpersonal psychotherapy had mean depression symptom and functional impairment scores respectively 14.0 points (95% CI 12.2–15.8; P < 0.0001) and 5.0 points (95% CI 3.6–6.4; P < 0.0001) lower than the control group. Similarly, the rate of major depression among those in the treatment arm (11.7%) was significantly lower than that in the control arm (54.9%) (P < 0.0001).

Participation in a 16-week group interpersonal psychotherapy intervention continued to confer a substantial mental health benefit 6 months after conclusion of the formal intervention.