OBJECTIVE:

The investigation of attention-deficit/hyperactivity disorder (ADHD) in girls raises complex questions of referral bias and selection criteria. The authors sought to determine whether they could recruit a research sample of comparably affected girls using a combination of sex-independent diagnostic criteria and sex-normed cutoffs on teacher ratings. They also report on the largest placebo-controlled crossover comparison of methylphenidate and dextroamphetamine in girls with ADHD.

METHOD:

Subjects were 42 girls with DSM-III-R/DSM-IV ADHD (combined type) contrasted to 56 previously studied boys with ADHD on comorbid diagnoses, behavioral ratings, psychological measures, psychiatric family history, and stimulant drug response.

RESULTS:

Girls with ADHD were statistically indistinguishable from comparison boys on nearly all measures. Girls exhibited robust beneficial effects on both stimulants, with nearly all (95%) responding favorably to one or both drugs in this short-term trial. Dextroamphetamine produced significantly greater weight loss than methylphenidate.

CONCLUSIONS:

This highly selected group of ADHD girls was strikingly comparable with comparison boys on a wide range of measures. The results confirm that girls with ADHD do not differ from boys in response to methylphenidate and dextroamphetamine and that both stimulants should be tried when response to the first is not optimal.