We explored the behavioral characteristics of 24 children with Perthes
' disease. Parents completed standard psychological self-administered
questionnaires regarding their child's behavior: the Conners Parent Sy
mptom Questionnaire and the Achenbach Child Behavior Checklist. One th
ird (33%) of the children had abnormally high scores in profiles assoc
iated with attention deficit hyperactivity disorder (ADHD) (impulsive,
hyperactive, and psychosomatic categories), much higher than the 3-5%
incidence of ADHD in the general population. They also tended to have
difficulties with school and social interaction skills. Certain epide
miologic characteristics of Perthes' disease (sex ratio, socioeconomic
status, geographic location, and associated congenital anomalies) are
also similar to those of ADHD, suggesting a correlation between the t
wo disorders.