When and How Should We Adjust Treatment?

Getting Meds Right: Is It in the Genes?

Genetic tests may be able to help those with ADHD find the most effective medication with a minimum of side effects.

By Troy Moore Updated on February 8, 2023

A DNA strand represents the genetic component of autism spectrum disorders.

ADHD is a complex disorder, and finding the right combination of medicines in the right amounts can be equally challenging. Based on your genes, you may metabolize certain medicines more slowly or quickly than another person. If the drug lingers in the body too long, it can build up and cause side effects. Likewise, if it passes through your body too quickly, it won’t work as effectively.

Luckily, recent advances in genetic testing may offer people with ADHD new insights into which medicines-and in what dosages-will deliver the best results. In some cases, gene-based testing reduces the need for trial and error, which can be frustrating and expensive.

Gene-based testing examines how a drug is metabolized in your body and indicates which types of medications are most likely to work best for you, lowering the likelihood of unpleasant side effects. Your results may help your doctor determine the right dosage levels for you.

Amphetamines, such as Adderall, cause nausea in many people. A genetic test may indicate how you’ll respond to this drug and if your doctor might be able to reduce side effects by altering your dosage.

Another example is the nonstimulant Atomoxetine. The drug passes through the body quickly. However, a small percentage of people are slow metabolizers of this type of drug, and it may take 24 hours to flush it out of their body. This may result in lingering side effects and ineffective treatment.

As always, it’s important to work closely with your doctor on drug choices and dosages. He or she can use testing results to help you achieve the best balance for your health.

Genetic testing may not be for everyone, but being informed about your health and treatment options is important. If you’re interested in learning more about about gene-based testing for ADHD, here is a quick primer:

> What should I look for in a genetic test? Look for a comprehensive test that focuses primarily on ADHD. Analyzing a wider range of appropriate genes gives you more information about which drugs will work best for you and the side effects that you are likely to experience.

> What does it cost? Genetic tests range in price from a few hundred dollars to several thousand dollars. The difference in cost isn’t due to the quality of the tests; it’s based on who will pay for it. The more expensive tests are usually covered partially by health insurance. The less expensive tests are often purchased by patients and can be as good as their more costly counterparts.

> Can a genetic test diagnose ADHD? Genetic science hasn’t reached the point where it can reliably test for the presence of ADHD. Neurological conditions are much more difficult to detect genetically, and the role of that a person’s environment plays in the disorder, and its severity, aren’t fully understood at this point.

Want to know more about gene testing? These resources are a great place to start:

• The Johns Hopkins-owned OMIM® tool, a free, online catalog of human genes and genetic disorders

• The PharmGKB, an online library that includes information such as medicine dosing guidelines, drug labels, possible gene-drug associations, and genotype-phenotype relationships.