title: Is Adult ADHD a Childhood-Onset Neurodevelopmental Disorder? Evidence From a Four-Decade Longitudinal Cohort Study.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Terrie E
authors.initials: TE
authors.lastname: Moffitt
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Renate
authors.initials: R
authors.lastname: Houts
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Philip
authors.initials: P
authors.lastname: Asherson
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Belsky
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: David L
authors.initials: DL
authors.lastname: Corcoran
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Maggie
authors.initials: M
authors.lastname: Hammerle
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: HonaLee
authors.initials: H
authors.lastname: Harrington
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Sean
authors.initials: S
authors.lastname: Hogan
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Madeline H
authors.initials: MH
authors.lastname: Meier
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Guilherme V
authors.initials: GV
authors.lastname: Polanczyk
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Richie
authors.initials: R
authors.lastname: Poulton
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Sandhya
authors.initials: S
authors.lastname: Ramrakha
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Karen
authors.initials: K
authors.lastname: Sugden
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Williams
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Luis Augusto
authors.initials: LA
authors.lastname: Rohde
authors.affiliation: From the Department of Psychology and Neuroscience, the Department of Psychiatry and Behavioral Sciences, School of Medicine, the Center for Genomic and Computational Biology, and the Social Science Research Institute, Duke University, Durham, N.C.; the Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London; the Department of Psychology, University of Otago, Dunedin, New Zealand; the Department of Psychology, Arizona State University, Tempe; the Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil; and the Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Allegre, Brazil.
authors.forename: Avshalom
authors.initials: A
authors.lastname: Caspi
mesh_terms: D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000453:epidemiology*; D002648:Child; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D065886:Neurodevelopmental Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D009483:Neuropsychological Tests; D009520:New Zealand / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies