Feasibility and preliminary efficacy of a theory-informed resistance exercise training single-arm intervention for major depression.

ABSTRACT

Many adults with major depressive disorder (MDD) do not receive effective treatment. The potential benefits of resistance exercise training (RET) are understudied and may be mechanistically related to cerebral blood flow changes. PURPOSE: To assess feasibility, acceptability, and preliminary efficacy of a 16-week, theory-informed RET trial for the treatment of MDD and explore changes in cerebral blood flow. METHODS: Ten adults with DSM-5-diagnosed MDD were enrolled in a single-arm, 16-week, twice-weekly, whole-body RET intervention, consistent with US and WHO Physical Activity resistance exercise guidelines. To build intrinsic motivation and develop exercise-preparatory habits, motivators and commitment were discussed weekly. Screening, enrollment, and intervention attendance and compliance rates documented feasibility. At baseline and weeks 8, 16, and 26, current MDD diagnosis, clinician-rated, and self-reported symptom severity were evaluated along with cerebral blood flow which was assessed as middle cerebral artery (MCA) mean blood velocity, conductance, and pulsatility. RESULTS: Nine participants completed the intervention. Strong feasibility and acceptability (98 % adherence, 93 % compliance, and 90 % retention) were found. MDD remission was reached by 8/9 participants at week 16 and persisted through week 26. There were large decreases in clinician-rated and self-reported symptoms at each assessment (Hedges' g = 0.84-2.13). There were small-to-moderate increases in MCA velocity (g = 0.32-0.57) and conductance (g = 0.20-0.76) across time, with minimal changes in pulsatility (all g < 0.21). CONCLUSIONS: Preliminary results suggest RET for MDD treatment is feasible and plausibly efficacious, finding large antidepressant effects. A sufficiently powered randomized controlled trial to assess RET's efficacy for treating MDD via potential cerebrovascular mechanisms is warranted.