Toward a broader definition of the age-of-onset criterion for attention- deficit hyperactivity disorder

Objective: To critique the age-of-onset criterion (AOC) for the diagnosis of attention-deficit hyperactivity disorder (ADHD) Method: The specific AOC of 7 years for symptoms producing impairment as part of the diagnostic criteria is examined from historical, empirical, conceptual, and pragmatic perspectives. Results: No support could be found for the continued use of this criterion for either clinical or research diagnostic purposes. While both empirical and conceptual grounds exist for viewing ADHD as a disorder that typically has its onset of symptoms during childhood, no support exists for the selection of age 7 years for onset of a valid disorder, either for symptom onset or for onset of impairment. Conclusions: Several reasons favor dispensing with a precise AOC, either for symptom onset or onset of impairment, not the least of which is that it is scientifically indefensible, poses unwarranted practical problems for the study of older adolescents and adults, and may be arbitrarily discriminatory. Until such time as an empirical justification can be marshaled for a precise AOC for ADHD, the current AOC should be either abandoned or generously broadened to include onset of symptoms during the entire childhood years, in keeping with its conceptualization as a childhood-onset disorder.