A Study Of Executive Function In Children With Attention Deficit Hyperactivity Disorder

Background Attention deficit hyperactivity disorder(ADHD), also known aschildren with Hyperkinetic Syndrome, is children’s common diseases of the centralnervous system, which can be divided into three subtypes: Predominantly hyperactive/impulsive type（HI）, Predominantly inattentive type（PI）, and Combined type（CT）.The present research has suggested that not only exist impulsivity and hyperactivitydisorder but also associated cognitive impairment in ADHD children. The executivefunction, an important part of cognitive function, is an essential attribute to produce allthe cognitive psychological processes, and it has been paid extensive attentions bymany researchers. There are many neuropsychological tools to assess the executivefunction. Stroop Word-color Test (SWT) and Wisconsin card sorting test (WCST) arethe classic paradigms of executive function evaluation, which is widely used in theadult nervous system diseases. However, it is seldom reported in researches on ADHDchildren. To investigate characteristics of executive function impairment in childrenwith ADHD and the difference between different subtypes of ADHD, SWT and WCSTwere applied to assess the executive function ofADHD children.Objective1.To investigate the characteristics of the executive function impairment inchildren with ADHD.2. To investigate the difference and characteristics in theexecutive function impairment between different subtypes of ADHD.3. To investigatethe role of SWT and WCST in assessing the executive function in ADHD Children.Methods1.Take the90cases (ADHD children aged from7to12) that conforms to thediagnosis standard of Diagnostic and Statistical Manual of Mental Disorders, DSM-IVas the research objects and select another80cases (healthy children with a matched age and education level) as control. SWT and WCST were applied to investigatecharacteristics of executive function in children with ADHD.2.90ADHD children ofdifferent subtypes (the HI type28, the PI type24and the CT type38) and80healthychildren were selected. To observe the characteristics and difference of executivefunction impairment between different subtypes of ADHD children, SWT and WCSTwere applied respectively in ADHD children and the normal control group.Results1.The result of the comparison between ADHD children group and comparison groupwith the method of SWT indicates that there are no statistical difference between thetwo groups in the time to complete the card number A and card number B（P＞0.05）,while there is a significant difference in the time to complete the card number C andInterference effect（P＜0.05～P＜0.01）. It shows the subjects consume time in wordreading and color reaction competition. Compared with normal control group, theADHD group shows an obvious interference effect. The difference was statisticallysignificant, and it suggests that there are ability defects in ADHD children to controlthe words meaning interference.2. The results in SWT between different subtypes ADHD children and normal controlgroup or within subtypes ADHD children indicate that there is no statistical differencein the time to complete the card number A and card number B（P＞0.05）, while thereis a significant difference in the time to complete the card number C and Interferenceeffect（P＜0.05～P＜0.01）. There is a statistical difference between PI group andcontrol group, CT group and control group and also PI group and CT group in the timeconsumption of interference effects（P＜0.05～P＜0.01）. There is no significantdifference between HI group and control group. It suggests that the ability of ADHDchildren of PI type and CT type to control the meaning of interference is lower thanthat of normal children, and there is an obvious decline of CT group to control themeaning of interference, while there is no statistical difference between ADHD children of HI type and control group（P＞0.05）.3. There is a significant difference in each index of WCST between the ADHD groupand control group（P＜0.05～P＜0.01）, which suggest that ADHD children existexecutive function defects in transformation in the process of cognitive processes andcomplex task management capabilities.4. Comparison in each index of WCST showed that there is a statistically significantbetween subtypes of ADHD and control group or within subtype groups （P＜0.05～P＜0.01）, which indicate that there exist differences in response characteristics indifferent subtypes of ADHD.Conclusion The study shows that the ability of ADHD children to control the meaningof interference, transformation capacity, and complex tasks of the management ability islower than that of normal children, which indicates that the executive functionimpairment exists in ADHD children. Different ADHD subtypes show differentinterference effects, which suggests there is a difference within the various subtypes.The reaction characteristics and ability of PI and CT are much lower than that of normalchildren. The reaction characteristics and ability of CT is much more serious than thatof PI, while the reaction characteristics and ability of HI is close to that of normalchildren, indicating that the hyperactivity performance of HI should be paid moreattention, however, PI and CT should be focused on attention and control ability.