The comparison of Wechsler intelligence test outcomes between children with Asperger syndrome and children with attention deficit hyperactivity disorder

Abstract

Objective To compare the intelligence quotient (IQ) between children with Asperger syndrome (AS) and children with attention deficit hyperactivity disorder (ADHD) in order to provide reliable evidence for diffe-rential diagnosis. Methods The intelligence of 141 children with AS, 154 children with ADHD and 102 normal control(NC)children aged 6-13 years old examined by the China-Wechsler Intelligence Scale for Children was analyzed, and the diagnoses of AS and ADHD was made according to the Fourth edition of the Diagnostic and Statistical Manual of Mental Disorder. Results The proportions of children at low level of IQ (borderline and mental retardation range) in children with AS and with ADHD group were both significantly higher than those of NC group.The proportions of children at top level of IQ (superior and very superior range) in ADHD group were significantly lower than those of AS and NC groups.In the AS group, higher proportions of verbal IQ (VIQ) at top level and performance IQ (PIQ) at low level were found.The average VIQ, PIQ and full IQ (FIQ) of the AS, ADHD and NC groups were (102.55±17.27, 91.31±16.01, 97.10±15.88), (95.39±13.49, 94.16±12.92, 94.40±12.78) and (104.06±13.66, 103.05±11.80, 103.91±12.92), respectively.The VIQ, PIQ and FIQ in ADHD group were lower than those in NC group significantly(P 0.05). The AS and ADHD group scored both lower than the NC group in the subtests ofcomprehension,coding,picture completionandpicture arrangement(P 0.05). The proportion of children having a VIQ-PIQ difference value more than 15 in AS group was 54.60%(77/141 cases), which was significantly higher than that in ADHD[22.07%(34/154 cases)]and NC groups[13.72%(14/102 cases)](P 0.05). The differences among scores on the three Kaufman factors were significant in AS group (P 0.05). Conclusions Compared with ADHD and normal control children, there are some unique intelligence profiles in children with AS, which show VIQ and PIQ separation, imbalance intelligence structure as well as strengths and weaknesses coexisting.Furthermore, children with ADHD and AS children share common features in some subtests scores. Key words: Asperger syndrome; Attention deficit hyperactivity disorder; Intelligence quotient