Patterns of familial aggregation of ADHD symptoms in parents of ADHD and no
n-ADHD children were examined. Within the ADHD sample, symptom aggregation
was examined as a Function of biological relationship, parent and child gen
der, and children's comorbid diagnoses. Participants consisted of parents o
f 579 children with ADHD, Combined Type participating in the multimodal tre
atment study of children with ADHD and parents of 288 normal control partic
ipants. Adult symptoms of ADHD were measured by both self-report and report
of a significant other. Results indicated that the parents of children wit
h ADHD had higher ratings of inattention/cognitive problems, hyperactivity/
restlessness, impulsivity/emotional lability, and lower self-concept than p
arents of children without ADHD on both self-report and other-report rating
s. Within the ADHD sample of children, other-report ratings of inattention/
cognitive problems and impulsivity/emotional lability were higher For biolo
gical parents compared to nonbiological parents whereas self-ratings were n
ot related to biological status. These findings support previous research d
ocumenting familial aggregation of ADHD and appear to strengthen the hypoth
esis that there is a genetic contribution to ADHD.