Pharmacogenomic Testing.
Can DNA Predict the Best Psychiatric Medication?
By Dr. Gregory Lyons, PsyD, LCPC.
10/22/2025.
For decades, psychiatric medication has been guided mainly by observation and patience. A client begins an antidepressant or mood stabilizer, waits several weeks, and adjusts based on side effects or limited benefit. This trial-and-error approach can be considered time-consuming and emotionally taxing for the clients and the psychiatrists, who may have endured multiple failed trials.
There could be hope on the horizon, because in recent years, a new tool has entered the clinical realm of pharmacogenomic testing, which uses genetic data of the client to help determine which medications may work best for an individual based on how their body metabolizes and responds to drugs. This can be described as DNA-guided prescribing and represents a major step toward personalized psychiatry.
How Pharmacogenomic Testing Works.
Pharmacogenomic testing examines specific genes that influence drug metabolism, transport, and receptor activity. Most psychiatric medications are metabolized by enzymes in the cytochrome P450 (CYP450) family, including CYP2D6, CYP2C19, and CYP3A4. Variants in these genes can make a person a poor, intermediate, extensive, or ultra-rapid metabolizer, affecting how efficiently the body processes certain medications. For example, a metabolizer of CYP2D6 may experience stronger side effects from fluoxetine or paroxetine, and an ultra-rapid metabolizer of CYP2C19 may clear escitalopram too quickly for it to be effective. Other genes such as ABCB1 (transport across the blood-brain barrier) and HTR2A (serotonin receptor subtype) may also influence response or side-effect sensitivity.
These tests are minimally invasive, allowing clients to participate easily. A cheek swab or blood sample is sent to a laboratory that analyzes genetic markers. The psychiatrist can then integrate this data with symptom history, diagnosis, and clinical judgment.
Common Commercial Tests.
Several commercial tests are marketed for psychiatric use:
GeneSight® (Myriad Neuroscience) — among the most widely used panels.
Genomind®, Myogenes, and Mayo Clinic’s PSYQP — offering similar gene coverage but differing in algorithms and interpretive tools.
The use of this approach to prescribing has several possible benefits. They can reduce trial-and-error in finding effective medication, and possibly improve estimated tolerability by anticipating side effects. This technique can also possibly foster faster stabilization for clients with a history of poor response.
A meta-analysis in Journal of Affective Disorders (Bousman et al., 2019) found that individuals who have a behavioral diagnosis and who were taking a prescription for their symptoms showed modest but statistically significant improvements in remission rates compared with treatment-as-usual groups.
For clients, the testing may offer reassurance that their difficulties may stem from biology rather than personal failure. For psychiatrists, it can have the possibility of assisting them in identifying why certain medications failed and guide the next steps.
The NIH and American Academy of Family Physicians (AAFP) recognize pharmacogenomic testing as potentially helpful for clients with multiple failed medication trials or sensitivity to side effects but recommend against its routine use for all patients.
Large-scale studies such as the GUIDED Trial (2018) reveal small yet measurable benefits in depression remission rates. However, effect sizes vary, and results must be interpreted cautiously given differences in clinical application and study design.
Limitations and Cautions.
Despite its promise, pharmacogenomic testing is not definitive.
Incomplete Predictive Power – Psychiatric conditions are polygenic and multifactorial. A handful of metabolic markers cannot capture the full complexity of emotional and behavioral health.
Clinical Interpretation Required – Reports may oversimplify results. A medication in the “red” category could still be effective at a different dose; one in “green” might still fail clinically. Judgment must remain with the clinician.
Regulatory Uncertainty – The FDA’s Table of Pharmacogenetic Associations lists only gene–drug pairs with sufficient evidence. Many marketed claims exceed this standard, and the agency warns that not all tests are clinically validated.
Cost and Accessibility – Testing may range from $200–$2,000, and insurance coverage varies widely.
Privacy and Ethics – Genetic data is protected health information. Clients should confirm that testing companies follow HIPAA standards and restrict data sharing.
The Role of Talk Therapy.
While pharmacogenomic testing can refine medication choices, it should never replace the therapeutic process. Medication may be able to regulate mood, energy, or sleep, but it does not address the underlying causes of distress.
Most psychiatrists agree that engaging in talk therapy alongside any medication regimen remains vital. Therapy provides space to examine the experiences, relationships, or belief systems that shape symptoms that could be aligned with experiences of trauma, grief, or learned coping patterns. Talk therapy, either in person or through telehealth, may allow clients to develop practical skills for managing daily stress, improving emotional regulation, and strengthening interpersonal functioning.
Even with medication, existing behavioral cycles can remain. Talk therapy supports clients in possibly identifying and examining these issues, in the hopes that the client may develop the skills to promote insight and long-term stability.
Therapeutic engagement further offers opportunities for psychoeducation, helping clients understand their diagnosis, the purpose of their medication, and potential side effects. Regular sessions create continuity: discussing recent experiences, exploring emotional reactions, and practicing mindfulness or behavioral strategies.
Ultimately, medication can reduce the intensity of symptoms, but therapy builds the capacity to live differently once relief begins.
In Conclusion.
Pharmacogenomic testing can be seen as an exciting step towards psychiatry’s evolution involving personalized care. It may be able to illuminate biological differences that influence treatment response, shorten the path to relief, and reduce frustration for clients and clinicians alike. Yet its promise must remain grounded in perspective. DNA can guide the map, but it cannot navigate the odyssey a client must take to identify their emotions that are linked to their behavioral issues.
It is also important for clients, especially those already prescribed psychiatric or behavioral medications, to stay informed about these emerging medical breakthroughs and understand that options such as pharmacogenomic testing exist so that clients can ask questions, engage their prescribers in conversation, and take a more active role in their treatment. This can possibly help them be aware of new tools which may assist them to make educated choices about their treatment, and talk with their psychiatrist about the possibility of future adjustments to their prescription regimen.
References.
American Academy of Family Physicians. (2021). Pharmacogenetic testing for psychiatric medication selection.
Bousman, C. A., Hopwood, M., et al. (2019). Pharmacogenetic tests and depression treatment outcomes: A meta-analysis. Journal of Affective Disorders, 254, 91–100.
Food and Drug Administration. (2020). Table of pharmacogenetic associations.
National Institutes of Health. (2022). Clinical implementation of pharmacogenomics in mental health.
Zeier, Z., Carpenter, L. L., et al. (2018). Clinical utility of pharmacogenetic testing in psychiatry. Pharmacogenomics and Personalized Medicine, 11, 1–12.