Background: Caffeine has been associated with a dose-dependent variety of mental health changes, which have been found to precede or be a complication of overactive bladder (OAB) symptoms after menopause. The current study examines the effects of low and moderate caffeine intake on anxiety, depression, sleep, and stress in postmenopausal females with OAB. Materials and Methods: Eighty-one females were randomized in a prospective, double-blind, placebo-controlled study. Participants were allocated to 200 mg/day caffeine, 400 mg/day caffeine, and placebo capsules for 1 week each in a crossover design and evaluated using validated mental health questionnaires. Symptoms during each treatment phase were measured using Beck Anxiety and Depression Inventory, Insomnia Severity Index, and Perceived Stress Scale. Linear regression models were used to examine the impact of low (200 mg/day) and moderate (400 mg/day) dose of caffeine and placebo on mental health. Results: Fifty-six female participants finished the study. The mean age was 69.2 years (58.0-84.0 years). Two females dropped out during the treatment phase with 400 mg/day caffeine intake due to side effects associated with headaches and nausea. Moderate dose of caffeine showed a small positive effect on mental health, specifically a decrease in anxiety during 7 days of exposure (p < 0.05). Conclusions: Moderate caffeine use may decrease anxiety in postmenopausal patients with underlying OAB, whereas depression, insomnia, and perceived stress were not affected by low-to-moderate caffeine intake. Our results support that counseling efforts on moderate caffeine consumption in postmenopausal patients underline that low-to moderate caffeine intake may be appropriate and possibly beneficial unless contraindicated due to other underlying conditions. Clinical Trials Registration: clinicaltrials.gov (NCT02180048).
Keywords: anxiety; coffee; depression; insomnia; outcome.