PRECISION PSYCHIATRY: Using Genetic Testing to Guide Medication Treatment Decisions
By Brittany Albright MD, MPH
Psychopharmacogenetic testing is a specialized form of genetic testing that aims to identify individual variations in genes that could affect one's response to medications, especially psychiatric medications like antidepressants, antipsychotics, and mood stabilizers. The basic principle is grounded in pharmacogenetics, the study of how genes affect a person's response to drugs. The goal is to tailor drug therapy to an individual’s genetic makeup to ensure maximum efficacy and minimize adverse effects.
I first learned about genetic testing to assist in medication prescribing while at my residency at Harvard. It was brand new at the time and not widely used. Since that time, the field of psychopharmacogenetics has exploded with a significant amount of research. We use this laboratory test (alongside great clinical judgment) to give us an idea of what medications patients are most likely to metabolize optimally. Better metabolism = theoretically better medication for that specific patient with the possibility of fewer side effects.
Here's how psychopharmacogenetic testing generally works:
Sample Collection
A DNA sample is usually collected using a cheek swab or a saliva sample. It is painless. This sample is then sent to a lab for analysis.
DNA Analysis
The lab isolates DNA from the sample and examines specific genes known to affect drug metabolism, drug receptors, and drug transporters. For instance, the gene CYP2D6 is known to be responsible for metabolizing many drugs, including certain antidepressants. Variations in this gene can make an individual a "poor metabolizer" or an "ultra-rapid metabolizer," which can have implications for drug effectiveness and risk of side effects.
Data Interpretation
The genetic data is interpreted to provide recommendations on which drugs are likely to be most effective, which may require adjusted dosages, or which should be avoided due to potential for adverse effects or ineffectiveness.
Report
A comprehensive report is usually sent to the healthcare provider, detailing the findings and recommendations. This report might suggest that the patient is likely to respond well to a certain class of antidepressants but may have an increased risk of side effects with another.
Treatment Plan
The healthcare provider reviews the report and may adjust the patient's medication regimen accordingly. However, it's important to note that psychopharmacogenetic testing is just one piece of the puzzle and should not replace a comprehensive medical evaluation. Other factors like medical history, other medications being taken, lifestyle, and the patient's current state of health are also critical for determining the best treatment plan.
Ongoing Monitoring
After medications are prescribed, the patient will usually be closely monitored to assess the treatment's effectiveness and to adjust the medication as needed.
Limitations
While promising, psychopharmacogenetic testing is not foolproof. Not all medications have a known genetic marker that can predict response, and the testing is not universally available or affordable. Moreover, the field is still evolving, and more research is needed to make these tests more accurate and reliable.
Overall, psychopharmacogenetic testing has the potential to revolutionize personalized medicine by providing more targeted treatment options for patients, but it's important to consult with healthcare providers for a comprehensive treatment approach. At Sweetgrass Psychiatry located in Mount Pleasant and Isle of Palms, SC, we offer two different genetic tests to assist in medication decisions. We offer GeneSight and Neuropharmagen. Some of these tests are covered by insurance. Out of pocket costs typically range from $330-399 (billed by the lab). We can have the test kit delivered to your home, you are welcome to stop by one of our offices, or you are welcome to go to the Precision Genetics lab in downtown Charleston.
ADDITONAL INFORMATION ABOUT NEUROPHARMAGEN:
“Neuropharmagen® enables providers to identify the safest psychotropic medication protocol for patients based on their genetic markers and other relevant factors. Finding the right medication for mental health conditions can often be challenging for patients and providers. Being able to quickly discern specific treatments and dosage amounts for antidepressants and other psychoactive drugs may increase a patient’s adherence and chance for a positive outcome.
Neuropharmagen® has shown to help medication response for adults and children around the globe with Anxiety Disorder, Bipolar Disorder, Depression, ADHD and other issues. Rigorous clinical trials have shown Neuropharmagen® to be effective in treating major depressive disorder and anxiety. “