Validity of DSM-IV attention-deficit/hyperactivity disorder for younger children

Little is known about the validity of the diagnosis of attention-deficit/hyperactivity disorder (ADHD) in young children. Moreover, the results of the DSM-IVfield trials raised concerns that inclusion of the new predominantly hyperactive-impulsive type of ADHD in DSM-IV might increase the likelihood of the diagnosis being given to active but unimpaired preschool and primary school children. Method: The validity of DSM-IV criteria for each subtype of ADHD was evaluated in 126 children, aged 4 through 6 years, and 126 matched comparison children. Probands and controls were classified by using structured diagnostic interviews of the parent and a USM-IVchecklist completed by the teacher. Results: Children who met DSM-IVcriteria for each subtype of ADHD according to parent and teacher reports differed consistently from controls on a wide range of measures of social and academic impairment, even when other types of psychopathology and other potential confounds were controlled. Conclusions: When diagnosed by means of a structured diagnostic protocol, all three DSM-IV subtypes of ADHD are valid for 4- through B-year-old children in the sense of identifying children with lower mean scores on measures of adaptive functioning that are independently associated with ADHD.