Pharmacogenetics of methylphenidate response in preschoolers with ADHD.

Published

Journal Article

OBJECTIVE: The authors explored genetic moderators of symptom reduction and side effects in methylphenidate-treated preschool-age children diagnosed with attention-deficit/hyperactivity disorder (ADHD). METHOD: DNA was isolated from 81 subjects in a double-blind, placebo-controlled, crossover methylphenidate titration. Parents and teachers completed ADHD symptom scales and side effect ratings for each of five randomly administered weekly conditions that included immediate-release methylphenidate 1.25, 2.5, 5.0, 7.5 mg and placebo given three times daily. Candidate genes hypothesized to influence stimulant effects or individual risks for ADHD were genotyped. RESULTS: Although the primary analysis did not indicate significant genetic effects, secondary analyses revealed associations between symptom response and variants at the dopamine receptor (DRD4) promoter (p=.05) and synaptosomal-associated protein 25 (SNAP25) allelesT1065G (p=.03) andT1069C (p=.05). SNAP25 variants were also associated with tics (p=.02), buccal-lingual movements (p=.01), and irritability (p=04). DRD4 variants were also associated with picking (p=.03). Increasing dose predicted irritability (p=.05) and social withdrawal (p=.03) with DRD4 variants. There were no significant effects for the dopamine transporter (DAT1). CONCLUSIONS: Emerging evidence suggests the potential for understanding the individual variability of response to and side effects of ADHD medications from the study of genetics, although additional research is required before these findings are proven to have clinical utility.

Full Text

Duke Authors

Cited Authors

  • McGough, J; McCracken, J; Swanson, J; Riddle, M; Kollins, S; Greenhill, L; Abikoff, H; Davies, M; Chuang, S; Wigal, T; Wigal, S; Posner, K; Skrobala, A; Kastelic, E; Ghuman, J; Cunningham, C; Shigawa, S; Moyzis, R; Vitiello, B

Published Date

  • November 2006

Published In

Volume / Issue

  • 45 / 11

Start / End Page

  • 1314 - 1322

PubMed ID

  • 17023870

Pubmed Central ID

  • 17023870

International Standard Serial Number (ISSN)

  • 0890-8567

Digital Object Identifier (DOI)

  • 10.1097/01.chi.0000235083.40285.08

Language

  • eng

Conference Location

  • United States