Is Adult ADHD a Childhood-Onset Neurodevelopmental Disorder? Evidence From a Four-Decade Longitudinal Cohort Study.

Published

Journal Article

Despite a prevailing assumption that adult ADHD is a childhood-onset neurodevelopmental disorder, no prospective longitudinal study has described the childhoods of the adult ADHD population. The authors report follow-back analyses of ADHD cases diagnosed in adulthood, alongside follow-forward analyses of ADHD cases diagnosed in childhood, in one cohort.Participants belonged to a representative birth cohort of 1,037 individuals born in Dunedin, New Zealand, in 1972 and 1973 and followed to age 38, with 95% retention. Symptoms of ADHD, associated clinical features, comorbid disorders, neuropsychological deficits, genome-wide association study-derived polygenic risk, and life impairment indicators were assessed. Data sources were participants, parents, teachers, informants, neuropsychological test results, and administrative records. Adult ADHD diagnoses used DSM-5 criteria, apart from onset age and cross-setting corroboration, which were study outcome measures.As expected, childhood ADHD had a prevalence of 6% (predominantly male) and was associated with childhood comorbid disorders, neurocognitive deficits, polygenic risk, and residual adult life impairment. Also as expected, adult ADHD had a prevalence of 3% (gender balanced) and was associated with adult substance dependence, adult life impairment, and treatment contact. Unexpectedly, the childhood ADHD and adult ADHD groups comprised virtually nonoverlapping sets; 90% of adult ADHD cases lacked a history of childhood ADHD. Also unexpectedly, the adult ADHD group did not show tested neuropsychological deficits in childhood or adulthood, nor did they show polygenic risk for childhood ADHD.The findings raise the possibility that adults presenting with the ADHD symptom picture may not have a childhood-onset neurodevelopmental disorder. If this finding is replicated, then the disorder's place in the classification system must be reconsidered, and research must investigate the etiology of adult ADHD.

Full Text

Duke Authors

Cited Authors

  • Moffitt, TE; Houts, R; Asherson, P; Belsky, DW; Corcoran, DL; Hammerle, M; Harrington, H; Hogan, S; Meier, MH; Polanczyk, GV; Poulton, R; Ramrakha, S; Sugden, K; Williams, B; Rohde, LA; Caspi, A

Published Date

  • October 2015

Published In

Volume / Issue

  • 172 / 10

Start / End Page

  • 967 - 977

PubMed ID

  • 25998281

Pubmed Central ID

  • 25998281

Electronic International Standard Serial Number (EISSN)

  • 1535-7228

International Standard Serial Number (ISSN)

  • 0002-953X

Digital Object Identifier (DOI)

  • 10.1176/appi.ajp.2015.14101266

Language

  • eng