Authors:
Aino Kohtala, Joona Muotka, and Raimo Lappalainen
Abstract:
Brief interventions can be viable treatment options worth consideration in addressing the growing need for treatments of subclinical and clinical depressive symptoms. However, there is uncertainty regarding the long-term benefits of these interventions. The aim was to examine the long-term (5-year) effects of a 4-session Acceptance and Commitment Therapy (ACT) intervention for low mood delivered by novice therapists in order to see whether lasting effects could be achieved cost-effectively with four intervention sessions. Originally, 57 self-referred clients were randomized into two groups: an intervention group and a waiting-list control group which received treatment later. The groups were combined both at the 6-month (n=48) and the 5-year (n=35) follow-up measurements to examine intervention effects. The results indicate a good effect size for depressive symptoms (the Beck Depression Inventory (BDI)): d=1.45 (CI 1.10–1.80) through the five-year study period. All in all, approximately 40% of the participants reported minimal to no depressive symptoms based on the primary outcome measure, the BDI (scores 0–9), both at post- and 5-year follow-up measurements.