Neurocognitive Subgrouping of Attention-Deficit/Hyperactivity Disorder (ADHD): A Cluster Analysis

• Other Authors: Chan, Hoi Ka (author.)
• Format: Others
• Language: English; Chinese
• Published: 2016
• Online Access: http://repository.lib.cuhk.edu.hk/en/item/cuhk-1292255

背景：認知功能障礙一般被視為「專注力不足/過度活躍症」行為表徵的誘因。過往的科學研究顯示患有「專注力不足/過度活躍症」的孩童往往在不同程度上受多種不同的認知功能障礙影響。這引申出一個科學上的疑問：這些不同程度或模式的認知功能障礙能否把患有「專注力不足/過度活躍症」的孩童分類成有臨床價值的群組？因此，科學界正尋求利用不同模式的認知功能障礙把患有「專注力不足/過度活躍症」的孩童分類。研究目的：本研究旨在探究患有「專注力不足/過度活躍症」的孩童的認知功能障礙模式。本研究嘗試以認知功能障礙模式把患有「專注力不足/過度活躍症」的孩童分類成有臨床價值的群組。研究方法：研究對象是327名年齡介乎6至12歲的男童。在參與者中，164人是患有「專注力不足/過度活躍症」的孩童，而餘下的163人則是發展正常的孩童。研究人員為所有參與者進行一系列的認知能力測試。本研究先以聚類分析 (cluster analysis) 為患有「專注力不足/過度活躍症」的孩童作分類。然後再以多變量變異數據分析 (MANOVA) 或卡方檢定 (chi-square test) 了解不同組別的「專注力不足/過度活躍症」孩童在不同方面的差異。研究結果：結果顯示患有「專注力不足/過度活躍症」的孩童可分成兩組。其中一組的孩童在多項「執行功能」(executive functions) 有顯著的困難，而另一組的孩童的「執行功能」與正常發展的孩童無異但其認知反應的一致性 (response consistency) 則較一般孩童參差。雖然這兩個組別的孩童的行為表徵並無差異，但結果顯示哌甲酯 (methylphenidate) 能較有效醫治有多項「執行功能」障礙的一組。結論：本研究印證了患有「專注力不足/過度活躍症」的孩童的認知功能障礙是多元化的。「專注力不足/過度活躍症」與兩個模式的認知功能障礙有關，其一為「執行功能」缺損，而另一個模式則是認知反應參差度。本研究所識別的分類有助改善日後針對「專注力不足/過度活躍症」患者的腦掃描及基因研究。 === Introduction. Neurocognitive deficits are assumed to underlie the behavioral symptoms of attention-deficit/hyperactivity disorder (ADHD). Research over the years has indicated a variety of these neurocognitive deficits, but no single one deficit appears to be dominant in all children with ADHD. This raises the question of whether there can be further subgrouping of ADHD children at the neurocognitive level. Aim. This study aimed to disentangle the heterogeneous neurocognitive deficits underlying ADHD. Objective. To achieve this, this study explored the possible existence of separable neurocognitive subgroups in children with ADHD. Method. One hundred and sixty-four ADHD boys and 163 typically developing boys, ages 6 to 12, were recruited. A battery of neurocognitive measures was administered. Cluster analysis was first conducted to identify subgroups of ADHD children based on their neurocognitive deficient profiles. Multivariate analysis of variance (MANOVA) or chi-square test was then employed to further explore the differences between subgroups. Results. Two ADHD subgroups are identified. One subgroup showed multiple executive function (EF) deficits, including inhibition deficit, poor interference control, distorted temporal information processing, slow processing speed, and delay aversion. The other subgroup, on the contrary, has intact EF but showed increased response variability. The two subgroups have comparable ADHD phenotypic severity and comorbidity patterns. However, ADHD children in the Executive Function Deficits subgroup are more responsive to medication (i.e., methylphenidate). Conclusion. Results support the neurocognitive heterogeneity of ADHD. EF deficits and response variability are two discernable neurocognitive profiles underlying and subgrouping ADHD children of comparable severity. This subgrouping has implications for medication response, and it offers potential endophenotypes for neuroimaging and genetic study. === Chan, Hoi Ka. === Thesis Psy.D. Chinese University of Hong Kong 2016. === Includes bibliographical references (leaves ). === Abstracts also in Chinese. === Title from PDF title page (viewed on …). === Detailed summary in vernacular field only.