Can Genetic Testing Reveal the Right Antidepressant?

By Joshua Plutchik and Lori Plutchik, M.D.

The treatment of clinical depression presents unique challenges, with many patients voicing concerns that echo a disheartening struggle: "I have tried every medication for depression, and nothing works." Or, "I cannot tolerate the side effects of any antidepressants." Such sentiments underscore the acute need for more tailored therapeutic strategies in mental health care.

Depression is a deeply debilitating disorder that affects over 21 million American adults annually. The repercussions are severe, leading to an astonishing loss of approximately 200 million workdays and inflicting an economic burden of approximately $20 billion each year. Beyond these stark statistics, the human cost is even more alarming. Depression profoundly erodes the quality of life, severely strains personal relationships, and, in severe cases, can culminate in suicide.

Regarding the need for personalized treatment approaches in mental health, consider a parallel with another medical specialty. Imagine seeking treatment for a swollen, painful knee. How would an orthopedist ensure that treatment effectively addresses the underlying cause? Typically, before suggesting surgery, they would perform a comprehensive assessment, including a physical exam, blood tests, and imaging. Why should psychiatric treatment be any different? Just as we would not rush to surgery for a swollen knee without thorough diagnostics, prescribing antidepressants without a comprehensive understanding of a patient’s genetic profile seems increasingly outdated. Pharmacogenetic testing offers critical data, guiding the selection of treatment strategies with precision.

The last decade has seen transformative advancements in psychiatric pharmacogenetics, thus potentially revolutionizing psychiatric care. Dr. Seema Patel, PharmD, BCPP, a medical science liaison at Genomind, elucidates the profound effect of this testing: "The way that pharmacogenetic testing can help you with your medications is being able to identify based on your unique genetics how you might respond to certain medications and what the risk of side effects would be with certain medications" (S. Patel, personal communication, March 24, 2024).

The Mechanics and Merits of Pharmacogenetic Testing

Pharmacogenetic testing is easily administered through a cheek swab in a clinical setting or at home. Many commercial insurance plans and Medicare now cover this. The concept is both simple and profoundly effective: by examining how individual genetic profiles influence drug metabolism and response, this testing pinpoints which class of antidepressants, such as SSRIs or SNRIs, are likely to be most effective for an individual. In addition, it can determine which specific medications are least likely to cause side effects.

Pharmacogenetic testing is also insightful about how non-pharmaceutical interventions, such as dietary supplements like l-methylfolate or magnesium, might benefit patients. The test even offers personalized insight into the benefits of exercise for mental health based on patients' genetic variants.

Scientific Validation of Pharmacogenetic Testing

The promise of pharmacogenetic testing extends beyond the theoretical realm, with robust research substantiating its efficacy. Dr. Patel cited a meta-analysis by Bousman and colleagues (2019) that indicated patients receiving pharmacogenetic-guided treatment exhibited a 70 percent higher probability of achieving remission when compared with those treated under standard care protocols. This supports earlier findings by Rosenblat and colleagues (2018), whose research demonstrated significantly enhanced response and remission rates in the treatment of depression when treatment was informed by genetic testing.

Further, Dr. Patel referenced a study by Swen and colleagues (2023), which found that pharmacogenetic-guided care reduced the risk of adverse drug reactions by 30 percent compared to traditional methods. Another compelling study by David and colleagues (2021) indicated that pharmacogenetic-guided patients were 50 percent less likely to be hospitalized than those under standard care.

The Future of Pharmacogenetic Testing in Psychiatry: A Holistic and Personalized Approach

It is crucial to note that while pharmacogenetic testing is a powerful tool, it should not be the sole basis for psychiatric treatment decisions. It is a component of a multifaceted approach that includes comprehensive clinical evaluations and ongoing patient monitoring. As research continues to advance and more psychiatrists adopt this technology, the hope is that fewer patients will have to endure the often debilitating journey through ineffective treatments. Pharmacogenetic testing promises a deeper understanding of individual responses to psychiatric medications but also paves the way for more personalized, effective mental health treatment.