Physical activity partially mediates associations between Big personality traits and incident generalized anxiety disorder: Findings from the irish longitudinal study on ageing

Background: This study aimed to examine associations of personality with generalized anxiety disorder (GAD) and physical activity (PA), PA with GAD, and PA mediates associations between personality and incident GAD. Methods: Participants aged >= 50 years completed the 60-item NEO-Five Factor Inventory questionnaire to assess personality and short-form International Physical Activity Questionnaire at baseline, and the Composite International Diagnostic Interview - Short Form to clinically assess GAD at baseline and 2, 4, and 6 years later. Participants who had GAD at baseline or reported having ever been told by a doctor that they had anxiety were excluded from analyses. Binary logistic regression quantified associations of the `Big Five' personality traits with PA and incident GAD, and associations of PA with incident GAD (i.e., GAD at any point during follow-up). The 'counterfactual approach' identified potential mediating effects of PA in the associations between personality traits and incident GAD. Results: Participants (n = 4582; 53.7% female) were aged 64.38 +/- 8.88 years. Incidence of GAD was 2.95% (n = 135). Extraversion (OR=1.160, 95%CI=1.087-1.237), openness (1.113, 1.043-1.188), and conscientiousness (1.083, 1.015-1.155) were positively associated with physical activity. Neuroticism was positively (2.335, 1.945-2.803), and extraversion (0.700, 0.563-0.797), conscientiousness (0.826, 0.693-0.985), and PA (0.655, 0.451-0.952) were inversely, associated with the incident GAD. Approximately 8.7% of the effect of extraversion and 8.8% of the effect of conscientiousness on GAD was due to mediation by PA only. Limitations: PA was self-reported Conclusions: Personality screening may help to identify older adults at-risk of anxiety who would benefit from participation in physical activity interventions.