ADHD News & Research

Study: Adults with ADHD Face Elevated Risk for 34 Physical Health Conditions

Adults with ADHD face elevated risk for sleep disorders, liver disease, obesity, pulmonary disease, and 30 other physical health conditions, according to a Swedish study that also suggests a shared genetic factor behind these associations.

August 11, 2021

Adults with ADHD are at greater risk than their non-ADHD counterparts for a wide range of physical health conditions, according to a recent Swedish study published in The Lancet Psychiatry 1 that highlights the importance of assessing older patients with ADHD for the presence of liver or pulmonary disease, among other physical conditions.

The study of roughly 4.8 million patient records found that adults with ADHD exhibit elevated risk for 34 of 35 physical conditions studied, including nervous system, respiratory, musculoskeletal, metabolic, circulatory, gastrointestinal, genitourinary, and skin conditions. The only condition for which individuals with ADHD did not exhibit increased risk was rheumatoid arthritis.

The individuals in the national register, born between 1932 and 1995, formed about 3.9 million full-sibling pairs and 470,000 maternal half-sibling pairs, which researchers used to evaluate the extent to which genetic and environmental factors account for the link between physical conditions and ADHD. About 1.29% of the individuals in the register (61,960) had diagnosed ADHD.

After adjusting for sex and birth year, individuals with ADHD showed most elevated risk compared to non-ADHD adults for (but not limited to):

Gastrointestinal

  • Alcohol-related liver disease (odds ratio of 4.70)
  • Fatty liver disease (odds ratio of 2.94)

Nervous system

Respiratory

  • Chronic obstructive pulmonary disease (odds ratio of 3.24)

Endocrine/metabolic

Further analysis between ADHD and nervous system disorders showed that genetic factors explained 28% of the correlation, while shared environmental factors explained 13%. Non-shared environmental factors explained 59%. For metabolic, respiratory, and musculoskeletal disorders, genetic factors explained up to 69% of the link, and the rest was explained by non-shared environmental factors.

The study also found that full siblings of individuals with ADHD had significantly increased risk for most physical conditions compared to maternal half-siblings, suggesting that shared familial factors contribute to the co-occurrence of the disorders. These findings also suggest that ADHD and the associated physical disorders share etiological components.

The findings, according to the authors, demonstrate the importance of rigorous medical assessment and care in adult patients with ADHD. They also highlight the need to investigate possible genetic factors between physical and psychiatric conditions, given that ADHD is frequently comorbid and shares a strong genetic basis with other mental disorders. The findings are also in line with a 2019 study that found that physical diseases are more prevalent in children with ADHD than their non-ADHD counterparts.

Sources

1Rietz, E., Brikell, I., Agnieszka, B., Leone, M. Chang, Z., Cortese, S. et.al. (July 6, 2021). Mapping phenotypic and aetiological associations between ADHD and physical conditions in adulthood in Sweden: a genetically informed register study. The Lancet Psychiatry.
DOI:https://doi.org/10.1016/S2215-0366(21)00171-1

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