title: Evidence for a general factor model of ADHD in adults.
abstract: OBJECTIVE
  To examine factor structures of Diagnostic and Statistical Manual of Mental Disorders (4th ed.) symptoms of ADHD in adults.
  
  
  METHODS
  Two sets of models were tested: (a) models with inattention and hyperactivity/impulsivity as separate but correlated latent constructs and (b) hierarchical general factor models with a general factor for all symptoms and separate specific factors for inattention and hyperactivity/impulsivity. Participants were 751 adults with ADHD. Two models with correlated factors and two general factor models of ADHD symptoms were tested.
  
  
  RESULTS
  The general factor model provided a better fit of the data than the correlated models. The general factor model with one general and three (inattention, motoric, and verbal hyperactivity/impulsivity) specific factors best accounted for the adults' symptoms.
  
  
  CONCLUSIONS
  These results suggest a unitary component to ADHD symptoms as well as dimensional specific factors. The replication of a general factor in adults suggests continuity of symptom presentation from childhood into adulthood. Clinical implications are discussed.
authors.affiliation: ADHD Clinic, Children's and Women's Health Centre, Vancouver, British Columbia, Canada.
authors.forename: Christopher
authors.initials: C
authors.lastname: Gibbins
authors.forename: Maggie E
authors.initials: ME
authors.lastname: Toplak
authors.forename: David B
authors.initials: DB
authors.lastname: Flora
authors.forename: Margaret D
authors.initials: MD
authors.lastname: Weiss
authors.forename: Rosemary
authors.initials: R
authors.lastname: Tannock
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological