Pre-adult attention-deficit/hyperactive disorder and later adverse health outcomes: the 1987 Finnish birth cohort study.

Whereas attention-deficit/hyperactive disorder (ADHD) has consistently been shown to be correlated with later risk of depression, anxiety, and substance misuse, the relationship with other adverse health endpoints, particularly somatic conditions, is uncertain. In a full-nation birth cohort study, we used a phenotype-wide approach to explore the influence, if any, of a ADHD diagnosis in childhood/adolescence on later disease and injury. Comprising 52594 children (25463 females) born in a single year with non-missing data, the 1987 Finnish Birth Cohort was generated from linkage of routinely collected data. ADHD diagnosis was captured from in- and out-patient hospital records up to age 18 years and study members continued to be surveilled for other diagnoses until 2020 (aged 33). Pre-adulthood, 0.43% (N = 228) of study members were diagnosed with ADHD. In people with ADHD, relative to population controls, there was a heightened risk of developing all of the 17 health endpoints examined. Of these associations, however, eleven were statistically significant after adjustment for age and sex, and five after further control for birth weight, family socioeconomic circumstances, study members' educational performance, and multiple testing (odds ratio; 99.7%): neurotic disorders (2.11; 1.25, 3.41); substance abuse disorder (2.26; 1.27, 3.79); poisoning (2.30; 1.02, 4.52); mood disorders (2.45; 1.49, 3.88); and epilepsy (4.55; 1.82, 9.55). Repeating the main analyses following data imputation (N = 54045) confirmed these associations with the emergence of a connection between psychotic disorders and antecedent ADHD (2.63; 1.34, 5.18). Overall, young people with ADHD in the present cohort experienced an increased future burden of psychiatric and neurological conditions but seemingly not somatic disorders.