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Little Evidence for Late-Onset ADHD in a Longitudinal Sample of Women

Objective: Individuals with late-onset symptoms of attention-deficit/hyperactivity disorder (ADHD) are presenting to providers at increasing rates. Recent birth-cohort studies reveal evidence for late-onset ADHD, but conclusions are challenged by measurement methods as well as presence of participant impairment and psychiatric comorbidities. We examined the occurrence of late-onset ADHD in a small but thoroughly investigated group of diverse (47% white) women followed from childhood to adulthood. Method: From a larger, 16-year longitudinal study, a subsample of young women without childhood ADHD (N = 87) was assessed at four time points between childhood and adulthood via a multimethod, multiinformant approach. We used a stepped diagnostic procedure to identify those who initially met symptom criteria for ADHD after childhood and then evaluated them for remaining DSM ADHD diagnostic criteria, including impairment, cross-situational symptoms, and comorbid diagnoses. Results: Of 87 participants, 17 met ADHD symptom criteria after childhood. Fifteen showed no evidence of childhood onset, 10 showed clear evidence of impairment, and nine had cross-situational symptoms. Of these nine, all but one showed clinically significant co-occurring or preexisting psychiatric diagnoses and/or substance use that might account for ADHD symptoms. Conclusions: Although 19.5% of women from our subsample without childhood ADHD met symptom criteria for ADHD during adolescence/adulthood, only one showed the needed combination of impairment and cross-situational symptoms without significant co-occurring mental health problems. It is possible that uncomplicated cases of adult ADHD do arise, yet we find little supporting evidence herein.