Adults with attention-deficit/hyperactivity disorder (ADHD) are at increased risk of a broad range of physical health conditions, according to a study in The Lancet Psychiatry, which reported the strongest associations for nervous system disorders and respiratory diseases.

“Our findings highlight the importance of assessing the presence of physical conditions in patients with ADHD,” researchers advised.

The study, which spanned a total 4.7 million people including 4.3 million sibling pairs in Sweden, is the first large-scale, register-based study to look at phenotypic and etiological associations between ADHD and physical conditions in adulthood. The average age at the end of follow-up was 47 years. Nearly 62,000 people in the full cohort had ADHD.

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Of 35 physical conditions included in the study, adults with ADHD showed increased risk of 34 conditions across nervous system, respiratory, musculoskeletal, metabolic, circulatory, gastrointestinal, genitourinary, and skin disease groups compared with adults without ADHD. The exception was rheumatoid arthritis.

According to researchers, nervous system disorders (specifically sleep disorders), and respiratory, musculoskeletal, and metabolic diseases showed the strongest associations with ADHD. Age-related diseases showing increased risk in adults with ADHD were cardiovascular disease, Parkinson’s disease, and dementia.

“Quantitative genetic modelling showed that these associations were largely explained by shared genetic factors (60%–69% of correlations),” researchers reported, “except for associations with nervous system disorders, which were mainly explained by nonshared environmental factors.”

Reference

Du Rietz E, Brikell I, Butwicka A, et al. Mapping phenotypic and aetiological associations between ADHD and physical conditions in adulthood in Sweden: a genetically informed register study. Lancet Psychiatry. 2021 Sep;8(9):774-783. doi: 10.1016/S2215-0366(21)00171-1