Research helps end guesswork in prescribing ADHD drug

May 3, 2010

Children with ADHD who carry a specific type of dopamine receptor gene respond better to the drug methylphenidate (MPH) than those without the genotype, according to new research from Cincinnati Children's Hospital Medical Center.

The findings come from the first-ever placebo-controlled pharmacogenetic drug trial for Attention Deficit/Hyperactivity Disorder in school age to evaluate variants of the DRD4 dopamine receptor gene using teacher ratings of children's symptoms.

The research makes progress toward ending the guesswork now involved in prescribing effective ADHD medications that deliver the greatest symptom improvement and fewest side effects, according Tanya Froehlich, M.D., a physician and researcher in the division of Developmental and Behavioral Pediatrics at Cincinnati Children's.

"We don't have a good way of predicting who will experience great improvement in ADHD symptoms with a particular medication, so we use a trial-and-error approach. Unfortunately, as a result finding an effective treatment can take a long time," Froehlich said. "With more information about genes that may be involved in ADHD medication response, we might be able to predict treatment course, tailor our approach to each child, and improve symptom response while decreasing health care costs."

The study was presented May 1 at the annual meeting of the Pediatric Academic Societies in Vancouver, Canada.

Dr. Froehlich and her colleagues tested 89 children between the ages of 7 and 11 who were not already taking stimulant medications for their ADHD. The researchers analyzed DNA from saliva samples to see if the children carried the 7-repeat version of the DRD4 gene, an increasing target of ADHD gene-based studies that has been linked to increased risk for the condition.

Children in the double-blind four-week trial were given one week each of placebo and three different doses of MPH for their ADHD. Parents and teachers assessed and scored the children's behavioral symptoms based on the Vanderbilt ADHD Parent and Teacher Rating Scales. In children with at least one copy of the 7-repeat DRD4 gene who took MPH, teachers reported greater improvement in symptoms with increasing doses compared to children who did not have any copies of the 7-repeat gene.

Going forward, Dr. Froehlich said researchers will be studying additional gene variants and their relationship to ADHD medication response. This includes that encode MPH drug targets, such as the dopamine transporter, as well as enzymes that help the body metabolize the drug. MPH (which goes by several brand names, including Ritalin and Concerta) is a stimulant frequently used to treat .

Explore further: Gene variant is associated with brain anatomy

Related Stories

Gene variant is associated with brain anatomy

August 6, 2007

A variant of the dopamine receptor gene may be associated with attention-deficit/hyperactivity disorder (ADHD) and with thinner tissue in areas of the brain that handle attention, but also appears associated with better clinical ...

Adult ADHD linked with dopamine levels

August 9, 2007

Adults with attention-deficit/hyperactivity disorder have a reduced response to the drug Ritalin, U.S. government scientists have found.

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

( -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.