Physical activity and generalized anxiety disorder: results from The Irish Longitudinal Study on Ageing (TILDA)

Generalized anxiety disorder (GAD) is prevalent and costly. Physical activity (PA) may protect against other mental health disorders, including depression, but its protective effect on GAD remains under-studied in the general population and unstudied among older adults. Therefore, the present study examines associations between meeting World Health Organization PA guidelines (i.e. ≥150 min of moderate PA, ≥75 min of vigorous PA or ≥600MET min of moderate and vigorous PA weekly) and the prevalence of probable GAD and incidence of GAD.

Participants (n  =  3950; 56.2% female) aged ≥50 years completed the short-form International Physical Activity Questionnaire and the abbreviated Penn State Worry Questionnaire at baseline and the Composite International Diagnostic Interview - Short Form to clinically assess GAD 2 years later. Prospective analyses included participants without probable GAD at baseline (n  =  3236).

Prevalence and incidence of GAD were 18.1% (n  =  714) and 0.9% (n  =  29), respectively. More respondents with GAD were female (72.2% vs 52.7%), aged 50-59 years (51.7% vs 38.7%), had normal waist circumference (52.7% vs 47.8) and smoked (20.4% vs 13.3%; all P <0.05). Meeting PA guidelines was associated with 25% and 63% lower odds of prevalent [odds ratio (OR)  =  0.75, 95% confidence interval: 0.64 to 0.88] and incident (OR  =  0.37, 0.17 to 0.85) GAD, respectively, in crude models, and 17% and 57% lower odds of prevalent (OR  =  0.83, 0.70 to 0.98) and incident (OR  =  0.43, 0.19 to 0.99) GAD, respectively, following adjustment for age, sex, waist circumference, social class and smoking.

In addition to established physical health benefits of PA, the present findings support the importance of increasing PA at the population-level for mental health.