Separating attention deficit hyperactivity disorder and learning disabilities in girls: A familial risk analysis

Objective: Familial risk analysis was used to clarify the relationship in g irls between attention deficit hyperactivity disorder (ADHD) and learning d isabilities in either mathematics or reading. Method: The authors assessed the presence of ADHD and learning disabilities in 679 first-degree relatives of three groups of index children: girls wit h ADHD and a comorbid learning disability, girls with ADHD but no learning disabilities, and a comparison group of girls without ADHD. Results: The risk for ADHD was similarly higher in families of ADHD proband s with and without learning disabilities, both groups had significantly hig her rates of ADHD than did families of the comparison girls. In contrast, o nly among relatives of ADHD probands with a learning disability was there a higher risk for learning disabilities. A strong (although statistically no nsignificant) difference emerged that suggested at least some degree of cos egregation of ADHD and learning disabilities in family members. There was n o evidence of nonrandom mating between spouses with ADHD and learning disab ilities. Conclusions: These results extend previously reported findings regarding th e relationship of ADHD and learning disabilities to female subjects and rai se the possibility that, in girls, the relationship between ADHD and learni ng disabilities is due to shared familial risk factors.