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 cri teria 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 fo r the combined type, and 43% of youths who met symptom criteria for th e predominantly inattentive type, did not manifest impairment before 7 years. For the latter two subtypes, requiring impairment before age 7 years reduced the accuracy of identification of currently impaired ca ses of ADHD and reduced agreement with clinicians' judgments. Conclusi ons: These findings raise questions about the validity of the DSM-IV d efinition of age of onset of ADHD. Marked differences in the ages of o nset of both symptoms and impairment for the three subtypes of ADHD su pport the validity of distinguishing among these subtypes in DSM-IV.