The association between adult attention-deficit/hyperactivity disorder and lifestyle factors: findings from the UK Biobank

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder, with diagnosis persisting in adulthood in up to 55% of cases. The association of ADHD with health-related behaviors in middle-aged and older adults remains relatively underexplored. We examined the relationship between ADHD in later adulthood and nutritional and lifestyle factors. This cross-sectional study included UK Biobank participants aged 40 years and older. Individuals reporting ADHD diagnosis were compared to age- and sex-matched individuals with a ratio of 1:10. Multivariate linear, logistic and multinominal regression models were used to assess the relationship of ADHD diagnosis with lifestyle factors, adjusting for sex, age, education, BMI, sleeplessness, alcohol intake, smoking and physical activity. Interaction with age and sex were additionally tested. The sample included 133 individuals with ADHD diagnosis and 1330 in the comparison group (mean age 56.0 ± 7.9 years, 42.8% men). After adjusting for potential confounders, ADHD was significantly associated with higher likelihood of being a former or current smoker (OR [95% CI], 2.2 [1.4, 3.3]; p < .001; 2.2 [1.2, 4]; p = .02 respectively), increased alcohol intake (OR [95% CI] 1.8 [1.1, 3]; p =.01), and higher energy intake (β [SE], 0.7 [0.4]; p < .001). The association between ADHD and smoking was stronger among men compared to women (p-for interaction=0.006). No significant associations were found between ADHD diagnosis and adherence to the Mediterranean diet or physical activity. Our findings, which demonstrate associations between adult ADHD diagnosis and health-related behaviors, underscore the need for tailored health promotion strategies to mitigate long-term health risks in this population.