The more, the merrier? Establishing a dose-response relationship for the effects of cognitive control training on...

Objective: Cognitive control impairments are frequently observed after remission from depression. There is evidence to show that cognitive control training (CCT) can reduce such impairments and related risk for recurrent episodes. However, it is currently unclear how many CCT sessions are required for short- and long-term effects. Method: This randomized controlled trial investigates the dose-response relationship of CCT in a sample of individuals with remitted depression (n = 216). Participants were randomly assigned to one of six arms, each receiving a different amount of training sessions (zero, one, five, 10, 15, or 20 sessions) over the course of 4 weeks, with each session lasting 15 min. Depressive symptoms and other cognitive and emotional transfer effects were examined shortly after training, as well as at 3- and 6-month follow-up. Results: We found task-specific, but no near cognitive transfer. Mixed-effects models showed that a minimum of 10 training sessions was required for a significant decrease in depressive symptoms shortly after training with medium effect sizes, but this was not maintained at 3- or 6-month follow-up. We observed reductions in perseverative thinking in all groups receiving 10 or more CCT sessions, which remained present until 6-month follow-up. Conclusions: A minimum of 10 CCT sessions is required for beneficial effects on depressive symptoms and perseverative thinking. Where perseverative thinking remained decreased long-term, this was not the case for depressive symptoms, indicating the need for continued training or the use of booster sessions to maintain training-related improvement. (PsycInfo Database Record (c) 2025 APA, all rights reserved).