title: Attention-Deficit/Hyperactivity Disorder Trajectories From Childhood to Young Adulthood: Evidence From a Birth Cohort Supporting a Late-Onset Syndrome.
abstract: The requirement of a childhood onset has always been a key criterion for the diagnosis of attention-deficit/hyperactivity disorder (ADHD) in adults, but recently this requirement has become surrounded by controversy.
  
  
  
  To investigate whether impaired young adults with ADHD symptoms always have a childhood-onset disorder in a population-based longitudinal study.
  
  
  
  Participants belonged to the 1993 Pelotas Birth Cohort Study, including 5249 individuals born in Pelotas, Brazil, in 1993. They were followed up to 18 to 19 years of age, with 81.3% retention. The data analysis was performed between August 8, 2015, and February 5, 2016.
  
  
  
  The ADHD status was first ascertained at 11 years of age using a screening instrument (hyperactivity subscale of the Strength and Difficulties Questionnaire) calibrated for a DSM-IV ADHD diagnosis based on clinical interviews with parents using the Development and Well-Being Assessment. At 18 to 19 years of age, ADHD diagnosis was derived using DSM-5 criteria, except age at onset. We estimated the overlap between these groups assessed at 11 and 18 to 19 years of age and the rates of markers of impairment in these 2 groups compared with those without ADHD.
  
  
  
  At 11 years of age, childhood ADHD (C-ADHD) was present in 393 individuals (8.9%). At 18 to 19 years of age, 492 individuals (12.2%) fulfilled all DSM-5 criteria for young adult ADHD (YA-ADHD), except age at onset. After comorbidities were excluded, the prevalence of YA-ADHD without comorbidities decreased to 256 individuals (6.3%). Children with C-ADHD had a male preponderance not observed among children without ADHD (251 [63.9%] vs 1930 [47.9%] male, P < .001), whereas the YA-ADHD group had a female preponderance (192 [39.0%] vs 1786 [50.4%] male, P < .001). Both groups had increased levels of impairment in adulthood, as measured by traffic incidents, criminal behavior, incarceration, suicide attempts, and comorbidities. However, only 60 children (17.2%) with ADHD continued to have ADHD as young adults, and only 60 young adults (12.6%) with ADHD had the disorder in childhood.
  
  
  
  The findings of this study do not support the assumption that adulthood ADHD is necessarily a continuation of childhood ADHD. Rather, they suggest the existence of 2 syndromes that have distinct developmental trajectories.
authors.affiliation: ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Arthur
authors.initials: A
authors.lastname: Caye
authors.affiliation: ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Thiago Botter-Maio
authors.initials: TB
authors.lastname: Rocha
authors.affiliation: Post-Graduate Program in Epidemiology, Universidade Federal de Pelotas, Pelotas, Brazil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Anselmi
authors.affiliation: Post-Graduate Program in Epidemiology, Universidade Federal de Pelotas, Pelotas, Brazil3Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Joseph
authors.initials: J
authors.lastname: Murray
authors.affiliation: Post-Graduate Program in Epidemiology, Universidade Federal de Pelotas, Pelotas, Brazil.
authors.forename: Ana M B
authors.initials: AM
authors.lastname: Menezes
authors.affiliation: Post-Graduate Program in Epidemiology, Universidade Federal de Pelotas, Pelotas, Brazil.
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Barros
authors.affiliation: Post-Graduate Program in Epidemiology, Universidade Federal de Pelotas, Pelotas, Brazil.
authors.forename: Helen
authors.initials: H
authors.lastname: Gonçalves
authors.affiliation: Post-Graduate Program in Epidemiology, Universidade Federal de Pelotas, Pelotas, Brazil.
authors.forename: Fernando
authors.initials: F
authors.lastname: Wehrmeister
authors.affiliation: Research Unit for Child and Adolescent Psychiatry, Psychiatric Hospital, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Jensen
authors.affiliation: Research Unit for Child and Adolescent Psychiatry, Psychiatric Hospital, Aalborg University Hospital, Aalborg, Denmark5Clinical Psychology and Epidemiology, Department of Psychology, University of Basel, Basel, Switzerland6Department of Child and Adolesce.
authors.forename: Hans-Christoph
authors.initials: HC
authors.lastname: Steinhausen
authors.affiliation: Department of Pediatrics, University of California, Irvine.
authors.forename: James M
authors.initials: JM
authors.lastname: Swanson
authors.affiliation: ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Christian
authors.initials: C
authors.lastname: Kieling
authors.affiliation: ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil8National Institute of Developmental Psychiatry for Children and Adolescents, São Paulo, Brazil.
authors.forename: Luis Augusto
authors.initials: LA
authors.lastname: Rohde
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000523:psychology*; D001938:Brazil; D002648:Child; D015331:Cohort Studies; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D000067562:Late Onset Disorders / Q000175:diagnosis* / Q000523:psychology*; D008137:Longitudinal Studies; D008297:Male; D055815:Young Adult