Genetic Testing: Finding the Right Medicine for You
Psychiatry Department — Patient Education
How Tempus genetic testing is helping our patients get better, faster — by working with your unique biology.
If you've ever tried a psychiatric medication that didn't work — or caused side effects that felt worse than your symptoms — you're not alone. The reason may not be the medication itself. It may be your genes.
Our psychiatry department offers Tempus pharmacogenomic (PGx) testing: a simple, cheek-swab genetic test that gives your psychiatrist information about how your body is likely to process and respond to psychiatric medications. This means less guesswork and more personalized care from the start.
Why Do Medications Affect People So Differently?
Anyone who has talked to friends or family members about mental health treatment has probably noticed something: the same medication can work remarkably well for one person and cause intolerable side effects — or no benefit at all — for someone else. This isn't a matter of willpower or attitude. It's biology.
A major reason comes down to enzymes in your liver — proteins that break down medications so your body can use them and eventually clear them. Two of the most important of these enzymes for psychiatric medications are called CYP2D6 and CYP2C19. The genes that encode these enzymes vary from person to person, and those differences can dramatically affect how quickly a drug is metabolized.
CYP2D6 and CYP2C19 play an important role in how many commonly prescribed antidepressants are metabolized, although other genes and non-genetic factors also influence medication response.
Individual Metabolizer Types — What They Mean for You
Slow metabolizer: Your body breaks down the medication too slowly. The drug builds up, potentially causing side effects even at standard doses.
Intermediate metabolizer: You process medication somewhat more slowly than average, which can alter drug levels and may increase the risk of side effects or require dosing adjustments.
Normal metabolizer: Your body processes medication at the expected rate — standard dosing guidelines tend to apply.
Rapid or Ultra-rapid metabolizer: Your body clears the medication too quickly, meaning standard doses may never reach effective levels in your system.
These differences matter enormously. Research published in Translational Psychiatry confirms that variants in CYP2C19 and CYP2D6 are associated with meaningfully different drug exposure levels and can predict treatment response for many antidepressants. A study in The Pharmacogenomics Journal found that patients who were non-normal metabolizers of one or both of these enzymes experienced significantly more adverse drug reactions compared to normal metabolizers.
What Is Pharmacogenomic (PGx) Testing?
Pharmacogenomics — often abbreviated PGx — is the study of how your genes affect your response to medications. A PGx test analyzes specific genetic variants to give your psychiatrist a clearer picture of which medications your body may process more slowly, more rapidly, or at expected rates.
The Tempus nP test is a clinically validated pharmacogenomic test designed specifically to inform medication selection and dosing for patients experiencing depression, anxiety, ADHD, and other mental health conditions. It uses next-generation sequencing (NGS) — a highly sophisticated method of reading your DNA — to generate detailed, personalized gene-drug interaction reports.
Importantly, the test's recommendations are grounded in evidence-based guidelines from major clinical authorities, including the FDA, the Clinical Pharmacogenetics Implementation Consortium (CPIC), PharmGKB, and the Dutch Pharmacogenetics Working Group. This means your provider receives actionable, peer-reviewed guidance — not just raw data.
The Numbers Tell a Compelling Story
65%
of patients tested had a potentially actionable result from two genes: CYP2D6 or CYP2C19. A higher percentage of patients tested had potentially actionable results from additional genes.
In a landmark analysis of over 15,000 patients tested with the Tempus nP assay, 65% had a potentially actionable CYP2D6 and/or CYP2C19 phenotype — meaning their genetic results had direct implications for how they should be treated. This finding, published in a peer-reviewed study, underscores how common genetic variation in drug metabolism truly is.
How the Test Works: Simple from Start to Finish
One of the most reassuring things about Tempus PGx testing is how easy it is for patients. There are no blood draws, no complicated procedures.
Your Provider Orders the Test
The Tempus nP test can only be ordered by a licensed medical professional — your psychiatrist or care team.
A Simple Cheek Swab
Sample collection uses a buccal (cheek) swab. Kits can even be mailed directly to your home.
Lab Analysis
Your sample is processed in a CLIA/CAP certified lab — the gold standard for clinical testing accuracy.
Results in ~2 Weeks
Your provider receives a personalized report with gene-drug interaction insights to guide your care.
The report is delivered to your provider — not dumped in a confusing patient portal without context. Your care team then reviews the findings with you and uses them as one important tool in crafting your treatment plan.
What the Report Tells Your Provider
The Tempus nP report doesn't just tell your provider what genes you have — it translates that information into clinically meaningful guidance. Your provider learns:
What's in Your Tempus PGx Report
Which medications your body is likely to metabolize well, slowly, or too quickly
Recommended dose adjustments based on your metabolizer status
Potential drug interactions based on your genetic profile (called "phenoconversion")
Emerging evidence findings — newer genetic insights that may be relevant as science evolves
The test covers a broad range of psychiatric medications, including many antidepressants, anti-anxiety medications, antipsychotics, and ADHD treatments. Because many of these drugs are processed by the same liver enzymes (CYP2D6 and CYP2C19 in particular), the results are highly relevant across a wide range of diagnoses and medications.
One piece of the puzzle
Pharmacogenomic testing is a powerful addition to your care — but it's one tool among many. Medications or dosing should never be changed without clinical consultation and careful monitoring. Your provider will use your PGx results alongside your full medical history, current symptoms, and personal preferences to make treatment decisions. Think of it as giving your provider a more detailed map — they're still the navigator.
Who Can Benefit?
You May Be a Good Candidate If You Have...
Tried multiple medications without finding one that works well
Experienced unexpected or severe side effects from psychiatric medications
Just started exploring medication options and want a more personalized starting point
A diagnosis of depression, anxiety, ADHD, bipolar disorder, or other mental health conditions
Biological relatives who have struggled to find effective psychiatric medications
Your Privacy Is Protected
Your identifiable health information is protected in accordance with HIPAA requirements and kept strictly confidential.
Get Started
Our psychiatry department provides Tempus nP pharmacogenomic testing as part of our commitment to personalized, evidence-based mental health care.
Sources
Tempus. Neurology & Psychiatry: AI & Genomic Solutions. Tempus.com. Updated February 2026. tempus.com/neurology-psychiatry
Tempus. Genetic Testing for Psychiatric Medication. Tempus Patients Portal. Updated February 2026. tempus.com/patients/neuro-psych
Tempus. Pharmacogenomic Actionability in >15,000 Patients with Next-Generation-Sequencing-Enabled Copy Number Variation and Novel Haplotype Detection. Tempus Publications. tempus.com/publications
Mostafa S, et al. The pharmacogenetics of CYP2D6 and CYP2C19 in a case series of antidepressant responses. Frontiers in Pharmacology. 2023. doi:10.3389/fphar.2023.1080117. frontiersin.org
Schmäl C, et al. Influence of combined CYP2C19 and CYP2D6 phenotypes on adverse drug reactions in patients with major depressive disorder. The Pharmacogenomics Journal. 2026. nature.com
Boland JR, et al. Pharmacogenomic insights in psychiatric care: uncovering novel actionability, allele-specific CYP2D6 copy number variation, and phenoconversion in 15,000 patients. PMC. 2024. pmc.ncbi.nlm.nih.gov
Arranz MJ, Munoz-Muriedas J. Pharmacogenomics of Antidepressant and Antipsychotic Treatment: How Far Have We Got and Where Are We Going? PMC. 2020. pmc.ncbi.nlm.nih.gov