Selecting effective antidepressants for the treatment Major Depressive Disorder (MDD) is an imprecise practice, with remission rates of just about 30% at the initial treatment choice. The potential of pharmacogenetic testing for making MDD treatment more precise, predictable and effective is exciting in theory. If effective, it would help patients to avoid trying different antidepressant medications before finding one that works best for their symptoms and with the least risk of adverse effects. However, because this is an evolving area of science, it is important to stay up-to-date as studies are published that evaluate pharmacogenetic testing. One notable recent study is the 2022 study by David W. Oslin, et al, which provides an updated status of pharmacogenetic testing for the treatment of MDD.
A Refresher on Pharmacogenetic Testing
Pharmacogenetic testing involves attempting to determine how a patient will respond to a medication in advance through genetic testing. Most pharmacogenomic testing focuses on variation in the genes that encode liver cytochrome P450 enzymes. The test results classify how an individual metabolizes medications: poor, normal, intermediate, and rapid metabolizing. This kind of testing could provide an alternative to the current approach of prescribing one antidepressant, evaluating its effectiveness, and then trying a different antidepressant if the first was unsatisfactory, and so on. Patients often have to try multiple antidepressants before finding the right one for them, and in the meantime, may suffer with their unabated symptoms and side effects.
A Study of Pharmacogenetic Testing for Depression
Methodology of The Study
Oslin, et al. conducted a study of 1,944 VA patients with Major Depressive Disorder, with the format of a randomized clinical trial to determine whether pharmacogenomic testing affects antidepressant medication selection and whether such testing leads to better clinical outcomes. This study is significant not only for its size, but also because it was not industry-sponsored, increasing its potential impartiality. The experimental group, called the “pharmacogenomic-guided group,” received their genetic testing results prior to treatment, while the usual care group did not receive their genetic testing results until after 24 weeks. The effectiveness of the treatment was measured at 4, 8, 12, 18, and 24 weeks.
Results and Conclusions
The study’s authors found that using pharmacogenetic testing prior to prescribing antidepressants made providers less likely to prescribe drugs that had a predicted drug-gene interaction. However, they found only a small effect of pharmacogenetic testing on symptom remission during the 24-week period of the study. The authors also noted that they found similar results for response and symptom reduction.
This study concludes that pharmacogenetic testing for Depression may not currently make much of a difference to the process of determining what antidepressant works best for a patient. Pharmacogenetic testing is expensive, so the authors suggest that it may be best not to recommend this for patients unless a significant benefit is expected specifically for an individual patient. An editorial published in the same journal is similarly cautious, arguing that pharmacogenetic testing (also called “pharmacogenomic testing”) for choosing antidepressants is “still a work in progress.”
However, it is important to remember that research is ongoing in this area. This study’s authors note that a limitation of their study was that both practitioners and patients were aware of whether they were in the pharmacogenomic-guided group or not, noting that this may mean that even the small impact of the testing that was observed was actually attributable to a placebo effect. The authors also described additional limitations, including that the particular genetic test that was used might not have the same results as others.
What Do The Limitations of Pharmacogenetic Testing for Depression This Mean For Your Depression Treatment?
While pharmacogenetic testing for Depression is not yet ready to be widely recommended, your Depression treatment at Mid City TMS will be guided by the professional judgment of a psychiatrist, Dr. Bryan Bruno, with over 30 years of experience. We will listen to you and take into account your treatment history, symptoms, and more, to get a complete picture of your needs. Your individualized treatment plan will be carefully constructed and periodically updated, with the improvement and remission of your symptoms always in mind.
Mid City TMS Provides Treatment for Major Depressive Disorder
While pharmacogenetic testing is still evolving, there are many empirically supported and long established treatments available for Depression. If you have been struggling to get relief from your symptoms, Mid City TMS provides treatment options including transcranial magnetic stimulation (TMS), Esketamine nasal spray (Spravato), and antidepressant medications. Contact us today to begin your journey to feeling better.
