Neuropsychological functioning in relatives of girls with and without ADHD

Background. A limited number of studies have examined neuropsychological functioning in the family members of ADHD youth, and none have focused exclusively on relatives of females. Method. Structured diagnostic interviews and neuropsychological batteries were administered to parents and siblings enrolled in a family study of girls with and without ADHD. Relatives were stratified into three groups: relatives of DSM-IV ADHD probands with ADHD (n = 106), relatives of ADHD probands without ADHD (n = 189) and relatives of controls without ADHD (n = 243). Analyses were also conducted on a subgroup of families in which more than one member had ADHD. Results. The neuropsychological battery as a whole distinguished affected and unaffected ADHD relatives from controls. The Wechsler Oral Arithmetic subtest, the Stroop Word, Color and Color-Word subscales were impaired in affected ADHD relatives, as were the WRAT-R Arithmetic and Reading subtests. Only the Stroop Color-Word and Interference subtests and the WRAT-R Arithmetic subtest showed significant impairments in unaffected relatives. In multiplex families, additional impairments were found in unaffected relatives on the Stroop Color subtest and the Wechsler Oral Arithmetic subtest. Analyses based on DSM-III-R diagnoses produced nearly identical results. Minor differences emerged across relatives of probands with different DSM-IV subtypes. Conclusions. Data were consistent with our previous study of relatives of boys with ADHD. Neuropsychological impairments in relatives of female ADHD probands were primarily associated with the diagnosis of ADHD, but subtle cognitive impairments that index familial vulnerability to the disorder may exist.