Language-based cognitive functioning in parents of offspring with ADHD comorbid for Tourette syndrome or learning disabilities

The parents of children diagnosed with attention deficit hyperactivity diso rder (ADHD) were examined for characteristics symptomatic of 2 comorbiditie s (Co) within their offspring with ADHD: Tourette syndrome (TS) and languag e-based learning disabilities (LD). A 2 x 2 multivariate analysis of varian ce design was used; the parents were divided according to whether the offsp ring with ADHD had TS (Co-TS) or not (No Co-TS) and whether offspring had L D (Co-LD) or not (No Co-LD). Parents (86 mothers and 70 fathers) were admin istered the short form of the Wechsler Adult Intelligence Scale-Revised (WA IS-R; Wechsler, 1981), subtests of the Woodcock-Johnson Cognitive and Achie vement Batteries (Woodcock & Johnson, 1989), and word fluency (semantic and letter; Benton & Hamsher, 1989; Wiig & Semel, 1987). The fathers of offspr ing with Co-TS were more likely to be diagnosed with LD and had lower WAIS- R Vocabulary, Arithmetic, and Picture Arrangement scores. In addition, when the WAIS-R full scale IQ was used as a covariate, these fathers had lower Woodcock-Johnson Oral Vocabulary, Spelling, and Reading scores (as measured by Letter-Word Identification). The mothers of children with Co-TS had low er WAIS-R Vocabulary scores. Parents of the children with No Co-TS showed a higher proportion of error patterns on the word fluency tasks involving re petitions and rule breaks. The findings show that it was the parents of the children with Co-TS, not the parents of the children with Co-LD, who showe d language-based learning problems. In separate discriminant analyses for t he fathers and mothers, when the aforementioned significant parental measur es were used as predictors, 81% of offspring with Co-TS were correctly clas sified as having a diagnosis of TS, solely on the basis of characteristics in their parents.