Featured Research

from universities, journals, and other organizations

Children with certain dopamine system gene variants respond better to ADHD drug

Date:
October 24, 2011
Source:
Cincinnati Children's Hospital Medical Center
Summary:
Children with certain dopamine system gene variants have an improved response to methylphenidate -- the most commonly prescribed medication for attention deficit hyperactivity disorder, according to new research. The finding that could help eliminate the guesswork from prescribing effective medications for children with ADHD.

Children with certain dopamine system gene variants have an improved response to methylphenidate -- the most commonly prescribed medication for Attention Deficit Hyperactivity Disorder -- a finding that could help eliminate the guesswork from prescribing effective medications for children with ADHD.

Researchers reporting their results in the Oct. 21 Journal of the American Academy of Child and Adolescent Psychiatry tested 89 children with ADHD between ages 7 and 11. They found that children with specific variants of the dopamine transporter (DAT) and dopamine receptor D4 (DRD4) genes showed greater improvement in hyperactivity and impulsivity after taking methylphenidate compared to children with alternative DAT and DRD4 versions.

"Physicians don't have a good way of predicting who will experience great improvement in ADHD symptoms with a particular medication, so currently we use a trial-and-error approach. Unfortunately, as a result, finding an effective treatment can take a long time," explained Tanya Froehlich M.D., lead investigator on the study and a physician in the division of Developmental and Behavioral Pediatrics at Cincinnati Children's Hospital Medical Center.

"With more information about genes that may be involved in ADHD medication response, we may be able to predict treatment course, tailor our approach to each child, and improve symptom response while decreasing health care costs," she added.

The study is the first-ever placebo-controlled pharmacogenetic drug trial for ADHD in school age children to evaluate the effects of dopamine system genes variants using teacher as well as parent ratings of children's symptoms. Given the importance of academic functioning for children with ADHD, Dr. Froehlich said it is crucial to consider medication impact at school as well as at home. Children in the study were not already taking stimulant medications for their ADHD.

Participants were prescribed one week each of placebo and three different doses of methylphenidate for their ADHD. Parents and teachers assessed and scored the children's behavioral symptoms based on the Vanderbilt ADHD Parent and Teacher Rating Scales.

The researchers analyzed DNA from saliva samples to see which ADHD-related gene types the children carried. They looked initially at four genes frequently implicated in ADHD -- DRD4, DAT, COMT and ADRA2A. DRD4 and DAT, the most well studied genes for ADHD, showed the strongest effects on methylphenidate dose-response in study participants, according to the researchers.

The DRD4 gene encodes the dopamine receptor protein, which helps control the synthesis and release of dopamine and the firing rate of neurons. The DAT gene encodes the dopamine transporter protein, which removes dopamine from the brain synapses.

Children who lack what is known as the DAT 10-repeat variant showed greater improvement after taking methylphenidate compared to those carrying the 10-repeat. Children without the DRD4 gene 4-repeat variant showed less symptomatic improvement with methylphenidate compared to 4-repeat carriers. A "repeat" is a short nucleotide coding sequences in a gene that is repeated.

Dr. Froehlich and her colleagues indicate in their study that although findings are promising, additional research is needed in larger patient samples to confirm current study findings and their clinical relevance.

Also collaborating on the study were researchers from the University of Cincinnati College of Medicine, the University of Arkansas for Medical Sciences, the University of Illinois (Chicago) and Duquesne University. Funding support came from the National Institute of Mental Health (NIH) and a Cincinnati Children's Hospital Medical Center Education and Research Therapeutics Award.


Story Source:

The above story is based on materials provided by Cincinnati Children's Hospital Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Tanya E. Froehlich, Jeffery N. Epstein, Todd G. Nick, Maria S. Melguizo Castro, Mark A. Stein, William B. Brinkman, Amanda J. Graham, Joshua M. Langberg, Robert S. Kahn. Pharmacogenetic Predictors of Methylphenidate Dose-Response in Attention-Deficit/Hyperactivity Disorder. Journal of the American Academy of Child & Adolescent Psychiatry, 2011; DOI: 10.1016/j.jaac.2011.08.002

Cite This Page:

Cincinnati Children's Hospital Medical Center. "Children with certain dopamine system gene variants respond better to ADHD drug." ScienceDaily. ScienceDaily, 24 October 2011. <www.sciencedaily.com/releases/2011/10/111021125513.htm>.
Cincinnati Children's Hospital Medical Center. (2011, October 24). Children with certain dopamine system gene variants respond better to ADHD drug. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2011/10/111021125513.htm
Cincinnati Children's Hospital Medical Center. "Children with certain dopamine system gene variants respond better to ADHD drug." ScienceDaily. www.sciencedaily.com/releases/2011/10/111021125513.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. Video provided by Newsy
Powered by NewsLook.com
Thousands Who Can't Afford Medical Care Flock to Free US Clinic

Thousands Who Can't Afford Medical Care Flock to Free US Clinic

AFP (July 23, 2014) America may be the world’s richest country, but in terms of healthcare, the World Health Organisation ranks it 37th. Thousands turned out for a free clinic run by "Remote Area Medical" with a visit from the Governor of Virginia. Duration: 2:40 Video provided by AFP
Powered by NewsLook.com
Stone Fruit Listeria Scare Causes Sweeping Recall

Stone Fruit Listeria Scare Causes Sweeping Recall

Newsy (July 22, 2014) The Wawona Packing Company has issued a voluntary recall on the stone fruit it distributes due to a possible Listeria outbreak. Video provided by Newsy
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins