Validity of the age-of-onset criterion for ADHD: a report from the DSM-IV field trials.

Objective: To examine the validity of the DSM-IV requirement of an age of onset of impairment due to symptoms before 7 years of age for the diagnosis of attention-deficit/hyperactivity disorder (ADHD).

Method: The validity of this criterion was examined in a clinic sample of 380 youths aged 4 through 17 years by comparing youths who met symptom criteria for ADHD and either did or did not display impairment before age 7 years.

Results: Nearly all youths who met symptom criteria for the predominantly hyperactive-impulsive subtype also met the age of onset of impairment criterion, but 18% of youths who met symptom criteria for the combined type, and 43% of youths who met symptom criteria for the predominantly inattentive type, did not manifest impairment before 7 years.

DSM-IV field trials for oppositional defiant disorder and conduct disorder in children and adolescents.

Objective: The purpose of the field trials for oppositional defiant disorder and conduct disorder was to select valid diagnostic thresholds for these disorders and to compare the psychometric properties of DSM-IV criteria for oppositional defiant disorder and conduct disorder with previous DSM diagnostic formulations.

Method: Structured diagnostic interviews, standardized clinician's validation diagnoses, and multiple measures of impairment were obtained for 440 clinic-referred children and adolescents aged 4-17 years.

Results: A diagnostic threshold of four symptoms of oppositional defiant disorder optimized identification of impaired children, improved agreement somewhat with the clinician's validation diagnosis, and had somewhat better test-retest agreement than DSM-III-R.