Authors:
Heidi Maria Kyllönen, Joona Muotka, Anne Puolakanaho, Piia Astikainen, Katariina Keinonen, & Raimo Lappalainen
Abstract:
Objective
This study examined the outcomes of a brief Acceptance and Commitment Therapy (ACT) intervention for depression delivered by novice therapists.
Method
Participants (N = 115) were randomized either to the brief (six sessions) ACT or to a waitlist control condition (WLC). Outcomes were assessed with diagnoses of depressive episodes (ICD-10) and questionnaires.
Results
After the 6-week intervention, diagnostic remission rates were 60% in the ACT and 22% in the control group. Further, 70% of the ACT participants were classified as either recovered or improved. The post-measurement between-group effect size for depression symptoms was large and favored the ACT group (BDI-II, d = 1.25). At the 3-year follow-up, the within-group effect sizes were encouraging (d = 1.11–1.77).
Conclusions
A 6-h ACT intervention delivered by novice therapists can lead to improvement in approximately 60–70% of depressed clients.