Exercise priming to enhance therapeutic bond and behavioral activation in CBT for MDD: a randomized controlled target-engagement trial with remission signal

Major depressive disorder (MDD) is a debilitating condition with frequent relapses. Augmentation strategies may improve psychotherapy outcomes, particularly if they enhance mechanisms of change. Using an experimental therapeutics approach, this pilot trial evaluated whether 30 min of individual moderate exercise immediately before individual cognitive behavioral therapy (ActiveCBT) engages two mechanistic targets (behavioral activation and therapeutic alliance) compared to a time- and attention-matched control (CalmCBT). Forty adults with DSM-5 MDD were severity-stratified and randomized to 8 weeks of ActiveCBT ( n = 19) or CalmCBT ( n = 21). Primary outcomes were the Working Alliance Inventory–Short Revised (WAI; Bond, Task, Goals subscales) and Behavioral Activation for Depression Scale (BADS). Depression outcomes included Hamilton Rating Scale for Depression (HAMD) response (≥50% reduction) and remission (HAMD