Among 4,160 Helsinki city employees aged 19-39, only vigorous leisure-time physical activity predicted fewer later psychotropic medication purchases; light and moderate activity showed no clear association. After full adjustment, 5 versus 0 hours per week of vigorous activity carried a hazard ratio of 0.79 (95% CI 0.68-0.91), roughly 23 fewer first purchases per 1,000 people over three years. The relationship was nonlinear, and 28.1% of participants bought psychotropic medication during 2014-2022 follow-up.
Psychotropic prescriptions serve as an objective, register-based proxy for treated depression and anxiety, avoiding the recall and reporting bias of self-rated symptom scales. That strength matters, yet the intensity-specific signal is the novel contribution, since most prior work lumps all activity together. Meta-analyses of randomized trials already support exercise for depressive symptoms, and this finding nudges toward intensity mattering, though it cannot prove it. Important caveats: activity was self-reported at one time point, so reverse causation is plausible, because people with emerging mental health problems may exercise less. Adjusting for prior medication helps but cannot eliminate this. The sample is 80% women and drawn from one municipal workforce, and medication purchases miss untreated or psychotherapy-treated cases. The effect also weakened after adjustment, a sign of residual confounding by health and lifestyle. This preprint has not been peer reviewed, so the estimates may change. Editorially, it is a modest, confirmatory observational result that flags vigorous activity as worth testing in trials, not a basis for prescribing exercise intensity.
