Gene testGene Testing for Psychiatric Medication: What It Can and Cannot Tell You. A plain look at what this test shows, where it helps, and where it stops.

Your body breaks down most medications and then clears them out. Much of that work happens in the liver, using proteins called enzymes. Your genes are the instructions for building those enzymes. Small differences in those instructions can make an enzyme work faster, slower or about the same as usual.

Two enzymes come up often with psychiatric medications. They are known by short names, CYP2D6 and CYP2C19. Each helps process a number of antidepressants, antipsychotics and other medications. A test looks for common gene variants that change how these enzymes work. Some panels check other genes too.

The test itself is simple:

• Most tests use a cheek swab or a saliva sample. Some use a small blood draw.
• You only need to do it once. Your genes do not change over time.
• A lab sends back a written report your prescriber reviews with you.

This is not the same as genetic testing for disease risk. It does not tell you whether you have a mental health condition or whether you will develop one.

The names vary a little from lab to lab, but usually look like this:

• Poor metabolizer: the enzyme works very slowly or not at all. A medication handled by that enzyme may build up in the body.
• Intermediate metabolizer: the enzyme works more slowly than usual.
• Normal metabolizer: the enzyme works as expected.
• Rapid or ultrarapid metabolizer: the enzyme works faster than usual. A medication may be cleared so quickly that it does less than expected.

Many reports also sort medications into colored categories, such as use as directed, use with caution, or consider an alternative. These can look like a ranking of which medication is best for you. They are not. They mostly summarize how your genes may affect the way your body processes each drug.

A general example: a report might show that you process a certain antidepressant slowly. Your prescriber might take that into account by choosing a different medication, starting more carefully, or watching more closely for side effects. The report does not make that choice for you.

The FDA Table of Pharmacogenetic Associations lists medications where certain gene variants may change how a drug is processed, or in some cases the risk of side effects. CYP2D6 and CYP2C19 appear on it alongside a number of antidepressants, antipsychotics and medications used for ADHD.

The FDA also points out important limits:

• A medication being on the table does not mean the FDA says you should be tested before taking it.
• Many of these gene and drug links have not been studied for their effect on how people actually feel and function.
• Genes are only one factor in how a person responds to a medication.
• Patients should not change their medications on their own based on a gene test. Talk with your prescriber first.

The FDA has also warned the public about some genetic tests that claim, without enough evidence, to predict how a person will respond to specific medications, including antidepressants. A careful prescriber will read your results as one input among many, not as a prescription.

A prescriber might bring it up, or you might ask about it, if:

• You have tried several medications without much benefit.
• You have had strong side effects, even at what are usually considered standard amounts.
• A medication seemed to work very differently for you than expected.

For teens, the same ideas apply, and parents are usually part of the conversation about whether testing makes sense.

Gene testing works best as part of a full picture: your history, other health conditions, other medications, substance use and what you have already tried. If you are new to psychiatric care, our guide What happens at a psychiatric evaluation walks through that first visit. When alcohol or drug use is part of the picture too, co-occurring disorders explains why both need attention.

Blackburn Clinical Services offers gene testing alongside psychiatric evaluation and medication management, so results can be read in the context of the whole person.

• It does not diagnose. It cannot tell you whether you have depression, anxiety, ADHD or any other condition.
• It does not pick the right medication. It can flag drugs your body may process differently. It cannot tell you which one will help you feel better.
• It does not predict everything. Age, other medications, liver health, smoking, diet and other factors also change how a drug works. Two people with the same results can respond differently.
• It only covers some medications and some genes. Many medications have little or no gene guidance yet.
• Insurance coverage varies. Some plans cover it in some situations and some do not. Ask the lab and your plan before testing. Our guide on paying for treatment has general tips on working with insurance.

Be cautious with at-home kits. Their results may not be accurate enough to guide treatment.

Most important: never stop or change a psychiatric medication on your own because of a gene test. Stopping some medications suddenly can cause withdrawal symptoms or a return of symptoms. Stopping alcohol or benzodiazepines suddenly can be medically dangerous. Talk to a doctor first.

Before testing, you might ask:

• Why do you think this test could help in my situation?
• Which genes and medications does this test cover?
• How might the results change what we do next?
• Will my insurance cover it, and how do I find out?

After testing, you might ask:

• What do my results mean for the medications I take now?
• Does anything in the report change your plan? Why or why not?
• Where will my results be stored, and who can see them?

It is fine to bring a family member or a written list, and to ask for any part of the report again in plain words.

The Genetic Information Nondiscrimination Act, known as GINA, is a federal law. In general terms:

• Health insurers cannot use your genetic information to decide whether to cover you or how much to charge.
• Most employers cannot use genetic information in hiring, firing, pay or promotions, and cannot require a genetic test.
• GINA does not cover life, disability or long-term care insurance.
• It does not apply to employers with fewer than 15 employees, or to the U.S. military.

Some states add more protections. Ask the lab how it stores your sample and data, whether it shares data for research, and how to have your sample destroyed. Read the consent form before you sign.

• FDA: Table of Pharmacogenetic Associations
• MedlinePlus (National Library of Medicine): Pharmacogenetic Tests
• MedlinePlus Genetics: What is pharmacogenomics?
• National Human Genome Research Institute: Genetic Discrimination
• 988 Suicide and Crisis Lifeline

Start with Where to start, or call us at (888) 305-5422 or email info@theblackburngroup.org. We can talk through whether a psychiatric evaluation, gene testing, medication management or a mix makes sense through Blackburn Clinical Services.

If you or someone you love is thinking about suicide, call or text 988 to reach the 988 Suicide and Crisis Lifeline. In an emergency, call 911.

• What Happens at a Psychiatric Evaluation
• What Is a Neuropsychological Evaluation?
• ADHD Evaluation for Teens and Adults

All guides →