J Psychiatry Neurosci 2015;40(3):280-287
Lizhou Chen, PhD*; Xiaoqi Huang, MD, PhD*; Du Lei, PhD; Ning He, MD; Xinyu Hu, MM; Ying Chen, PhD; Yuanyuan Li, MD; Jinbo Zhou, MM; Lanting Guo, MD; Graham J. Kemp, MA, DM; Qiyong Gong, MD, PhD
Background: Attention-deficit/hyperactivity disorder (ADHD) is an early-onset neurodevelopmental disorder with multiple behavioural problems and executive dysfunctions for which neuroimaging studies have reported a variety of abnormalities, with inconsistencies partly owing to confounding by medication and concurrent psychiatric disease. We aimed to investigate the microstructural abnormalities of white matter in unmedicated children and adolescents with pure ADHD and to explore the association between these abnormalities and behavioural symptoms and executive functions.
Methods: We assessed children and adolescents with ADHD and healthy controls using psychiatric interviews. Behavioural problems were rated using the revised Conners’ Parent Rating Scale, and executive functions were measured using the Stroop Colour-Word Test and the Wisconsin Card Sorting test. We acquired diffusion tensor imaging data using a 3 T MRI system, and we compared diffusion parameters, including fractional anisotropy (FA) and mean, axial and radial diffusivities, between the 2 groups.
Results: Thirty-three children and adolescents with ADHD and 35 healthy controls were included in our study. In patients compared with controls, FA was increased in the left posterior cingulum bundle as a result of both increased axial diffusivity and decreased radial diffusivity. In addition, the averaged FA of the cluster in this region correlated with behavioural measures as well as executive function in patients with ADHD.
Limitations: This study was limited by its cross-sectional design and small sample size. The cluster size of the significant result was small.
Conclusion: Our findings suggest that white matter abnormalities within the limbic network could be part of the neural underpinning of behavioural problems and executive dysfunction in patients with ADHD.
*These authors contributed equally to this work.
Submitted Jul. 18, 2014; Revised Nov. 15, 2014; Accepted Dec. 2, 2014; Early-released Apr. 8, 2015.
Acknowledgments: This study was supported by the National Natural Science Foundation (Grant Nos. 81030027, 81227002,81171488 and 81220108013), National Key Technologies R&D Program ( Program No. 2012BAI01B03) and Program for Changjiang Scholars and Innovative Research Team in University (Grant No. IRT1272) of China. Dr Gong would also like to acknowledge his Visiting Adjunct Professor appointment in the Department of Psychiatry at the Yale School of Medicine, Yale University, USA.
Affiliations: From the Huaxi MR Research Center, Department of Radiology, West China Hospital of Sichuan University, Chengdu, China (L. Chen, Huang, Lei, Hu, Gong); Department of Psychiatry, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, China (He, Y. Chen, Li, Zhou, Guo); Magnetic Resonance and Image Analysis Research Centre and Institute of Ageing and Chronic Disease, University of Liverpool, UK (Kemp).
Competing interests: None declared.
Contributors: L. Chen, X. Huang, L. Guo and Q. Gong designed the study. L. Chen, X. Huang, D. Lei, N. He, X. Hu, Y. CHen, Y. Li and J. Zhou acquired the data, which L. Chen, X. Huang, D. Lei, N. He, L. Guo, G. Kemp and Q. Gong analyzed. L. Chen and X. Huang, wrote the article, which all authors reviewed and approved for publication.
Correspondence to: Q. Gong, Huaxi MR Research Center, Department of Radiology, West China Hospital of Sichuan University, Chengdu 610041, China; firstname.lastname@example.org