Study on executive function in clinical subtypes of attention deficit hyperactivity disorder

Objective To explore the executive function in clinical subtypes of attention deficit hyperactivity disorder(ADHD). Methods 19 children with ADHD/ inattentive type(ADHD-I), 13children with ADHD/ hyperactive-impulsive(ADHD-HI) 33 children with ADHD/combined type(ADHD-C) and 30 normal children were tested by Stroop test (included Stroop C and Stroop CW), modified Wisconsin card sorting test(M-WCST), tower of Hanoi, digital span and verbal fluency. Results The scores of Stroop C and Stroop CW, digit inverse reciting, tower of Hanoi and WCST in the children with ADHD were worse than those in normal control((104.8±4.0), (105.9±4.2), (104.8±3.7), (104.8±4.0), P<0.05; (84.0±9.2), (84.8±7.9), (78.2±7.8), (92.2±7.1), P<0.01; (4.0±1.8), (3.7±1.2), (3.8±1.5), (5.1±1.6), P<0.01; (3.0±1.0), (3.3±1.0), (2.7±1.3), (3.8±1.3), P<0.01; (4.1±1.6), (4.2±1.9), (4.3±2.1), (5.4±1.7), P<0.05; (6.6±3.2), (6.7±2.4), (8.0±2.9), (5.3±2.4), P<0.01; (10.2±2.8), (11.1±3.8), (12.3±4.0), (9.4±3.2), P<0.05). The scores of Stroop CW in the children with ADHD-C were worse than those in other two subtypes(P<0.01). Conclusion The executive functions of the children with ADHD are impaired, including poor response inhibition, working memory, planning and cognitive flexibility. The dysfunction of response inhibition is possible an index to discriminate the subtypes of ADHD. Key words: Attention deficit hyperactivity disorder; Subtype; Executive function