Gene-environment Interactions and Brain Functional Connectivity in Attention Deficit Hyperactivity Disorder

Gene-environment Interactions and Brain Functional Connectivity in Attention Deficit Hyperactivity Disorder

Gene-environment Interactions and Brain Functional Connectivity Associated With Norepinephrine System Genes in Attention Deficit Hyperactivity Disorder

The aims of the current study are to examine gene-environment interactions associated with norepinephrine (NE) system genes (ADRA2A, SLC6A2) in ADHD, and to evaluate whether genetic changes in norepinephrine pathway are associated with differences in functional connectivity of white matter fiber tracts, as measured by diffusion tensor imaging (DTI). Furthermore, this study aims to examine neurobiological markers, such as intermediate neuroimaging phenotypes or neuropsychological endophenotypes associated with the pathophysiology of ADHD. Through evaluating drug responses and side effects with the associated measures of clinical, neuropsychological and neuroimaging characteristics, investigators would like to investigate predictors of treatment response associated with NE system genes in ADHD.

Participants were treated with methylphenidate (ranging from to 63mg) for 8 weeks. Doses of methylphenidate were titrated depending on symptoms and adverse eff ects at the 2nd and 4th weeks of treatment.

Attendtion-deficit hyperactivity disorder (ADHD) Rating Scale-IV is the sum of 18 questions, ranging from 0 (no symptoms) to 54 (worst possible symptoms). Change from baseline ADHD Rating Scale-IV scores at 8 weeks was calculated as baseline minus 8 weeks.

Clinical Global Impression-Improvement (CGI-I) scale is a one-item measure evaluating the change from the initiation of treatment on a seven-point scale: "Compared to the patient's condition at baseline [prior to medication initiation], this patient's condition is: 1=very much improved since the initiation of treatment; 2=much improved; 3=minimally improved; 4=no change from baseline (the initiation of treatment); 5=minimally worse; 6= much worse; 7=very much worse since the initiation of treatment. Clinical Global Impression-Improvement was measured at 8 weeks.

Inclusion Criteria: Clinical diagnosis of Attention-deficit Hyperactivity Disorder 6-18 years old Exclusion Criteria: History of neurological diseases, including convulsive disorders or brain damage IQ below 70 Pervasive developmental disorder (autism) Language difficulties or learning disorders (reading disorders, mathematics disorders and disorders of written expression). Tourette's syndrome Bipolar disorder Psychosis

Kim JI, Kim JW, Shin I, Kim BN. Effects of Interaction Between DRD4 Methylation and Prenatal Maternal Stress on Methylphenidate-Induced Changes in Continuous Performance Test Performance in Youth with Attention-Deficit/Hyperactivity Disorder. J Child Adolesc Psychopharmacol. 2018 Oct;28(8):562-570. doi: 10.1089/cap.2018.0054. Epub 2018 Jun 15.

Kim JW, Sharma V, Ryan ND. Predicting Methylphenidate Response in ADHD Using Machine Learning Approaches. Int J Neuropsychopharmacol. 2015 May 10;18(11):pyv052. doi: 10.1093/ijnp/pyv052.

Hong SB, Zalesky A, Park S, Yang YH, Park MH, Kim B, Song IC, Sohn CH, Shin MS, Kim BN, Cho SC, Kim JW. COMT genotype affects brain white matter pathways in attention-deficit/hyperactivity disorder. Hum Brain Mapp. 2015 Jan;36(1):367-77. doi: 10.1002/hbm.22634. Epub 2014 Sep 9.