Association between childhood ADHD problems and premature mortality: identifying modifiable cardiovascular mechanisms in a UK population cohort

Background Individuals with attention deficit hyperactivity disorder (ADHD) are at increased risk of premature mortality, but the mechanisms that underlie this association after young adulthood are unknown. As ADHD is associated with cardiovascular disease, modifiable cardiovascular risk factors could contribute to links between ADHD and premature mortality. Aims This study aims to investigate whether specific cardiovascular risk factors explain the association between childhood ADHD problems and a higher risk of premature mortality. Methods We used the UK 1958 birth cohort, the National Child Development study (NCDS), and linked death register data to examine whether children with ADHD problems at age 7 years were at higher risk of premature mortality by age 58 and if specific modifiable cardiovascular risk factors, measured at midlife (age 44 years), mediated this association using path analysis. Results A total of 8,016 individuals completed both the age 7 ADHD assessment and the age 44/45 biomedical assessment. Of these individuals, 231 (3.1%) were grouped as likely having ADHD. The odds ratio (OR) for deaths ( n = 251) in the ADHD group versus the non-ADHD group was 1.86 (95% CI 1.08–3.17). The risk was largely explained by cigarette smoking status at midlife and by a higher waist–hip ratio (a measure of obesity). Conclusions Childhood ADHD problems are associated with a higher risk of premature mortality by age 58. This risk seems to be mainly explained by two potentially modifiable cardiovascular risk factors: obesity and smoking. These risks should be prioritized for preventative interventions to reduce the risk of premature mortality in those with a history of ADHD.