Behavioral Activation for Depression and Habitual Rumination

Depressive rumination, a negative thinking style characterized by repetitive and passive thoughts about the causes, meanings, and consequences of one's feelings and distress, is often described as being a habitual response tendency that forms a vulnerability to depression. Behavioural Activation (BA) is an effective treatment for depression but little is known of mechanisms of changes during a successful treatment completion and for whom the treatment benefits the most. The main purpose of the study is to investigate whether habit-like mood-reactive rumination will change during Behavioral Activation treatment for current depression and mediates symptom changes in the treatment. Important moderators of change will also be investigated (i.e. history of early life stress and cognitive flexibility). We aim to provide individual BA treatment for up to 120 currently depressed participants (from 90 to 120 participants) in 12 treatment sessions over 11 weeks. Measures are obtained at pre-treatment, during treatment, at post-treatment and at 6 month follow up.

NCT Number	NCT06322420
Lead Sponsor	University of Iceland Collaborators: Icelandic Research Center
Conditions	Major Depressive Disorder
Enrollment	120 participants
Start Date	2024-02-09
Primary Completion	2026-06-11 (estimated)
Study Completion	2026-12-11 (estimated)
Updated on ClinicalTrials.gov	2026-06-26