With the rapid advances in the field of genetics and growing understanding of the human brain and body, the past few decades have seen a rise in precision (or personalized) medicine. We know that while two people may share the same symptoms or clinical diagnosis, that does not mean that they will find a relief with the same medication. Nonetheless, we continue to see the same trial and error practices when treating with psychiatric medications, despite knowing that an individual’s genetics can significantly impact medication response.
What is Pharmacogenomics or Pharmacogenetics (PGx)?
Pharmacogenetics is a field of study combining the science of pharmacology and genomics to understand how an individual’s genetics may influence the response to drugs. PGx testing has broad implications in mental health treatment, as the Food and Drug Administration (FDA) has over 270 medications with genetic-based guidance on their manufacturing labels. Of those, 36 are mental health-related medications.
PGx testing cannot determine “the perfect drug” for anyone; however, it provides valuable genetic insight to aid a clinician in the decision-making process in conjunction with reviewing the patient’s symptoms, past treatment responses, family history, and treatment goals. Our gene panel assesses genes that may impact:
- How the person’s body may metabolize and absorb medications.
- How sensitive a person’s body may be to certain medications (which may increase or decrease their risk of medication-related side effects).
Utilizing PGx results provides clinicians with more patient-specific information, which acts as another clinical tool to use when selecting treatments and doses for each individual patient.
Growing Evidence Supporting PGx
Though pharmacogenetic testing (PGx) has been around for several years, there has been some hesitation in the mental health community to widespread adoption of this practice. Some clinicians believe this testing is “experimental” or “may not be ready for prime time.” Other clinicians have not been sufficiently educated how to interpret the results and have difficulty explaining the results to their patients. As experience with this tool has grown (and the tests have become more sophisticated by including more genes of interest), PGx testing is increasingly acknowledged by accredited institutions and respected healthcare establishments. For example:
- The FDA has stated, “Pharmacogenomics can play an important role in identifying responders and non-responders to medications, avoiding adverse events, and optimizing drug dose.”
- The American Psychiatric Association’s (APA) updated 2020 schizophrenia treatment guidelines recognized that treatment with antipsychotics “can be influenced by genetic differences and metabolic enzyme activity.”
- The APA also acknowledged that the CYP2D6 gene (one gene that is commonly analyzed in PGx testing) “likely has the greatest potential for impact on antipsychotic medication metabolism.”
- In a random-effects meta-analysis, (i.e., a study of studies), patients with Major Depressive Disorder tested with PGx were 71% more likely to achieve remission on their medication regimen compared to participants receiving treatment as usual.
Who is PGx Testing Best Suited for?
It is important for patients to understand that pharmacogenetic testing does not yet provide clinical insights regarding an individual’s diagnosis. Rather, PGx testing is done to help streamline a person’s treatment path to the appropriate medication and dosage, potentially reducing the “trial and error” that often happens with real-world “treatment as usual” situations. Ideal candidates for this testing include:
- People worried about developing side effects to medications or those who already have had significant side effects to past trials of psychiatric medications.
- People with comorbidities: Treating one psychiatric condition is a challenge on its own, thus additional diagnoses can compliment treatment substantially. Patients often need other medications to treat comorbid conditions, which may increase the risk for drug-drug interactions. To help account for both drug-gene and drug-drug interactions, clincians utilizing the PGx testing through Genomind may have access to advanced software that helps manage these potentially complex interactions.
- Patients with specific lifestyle factors: Lifestyle factors, like coffee consumption or smoking tobacco or marijuana, may influence drug blood levels and, therefore, drug tolerability and response.
Patients interested in learning more about themselves and their own biology: One important aspect about pharmacogenetic testing is that a person’s genes do not change. This means that the results are theoretically good for life and can be used down the road for alternative conditions (or alternative medications) as needed.
The explosion in genetics and genetic testing has had far-reaching impacts in society and medicine. Many are increasingly comfortable with sharing their genetic information to learn more about their ancestry, risk of developing disease, and—in the mental health space—one’s potential response to ongoing or proposed medication. PGx testing is gaining increased acceptance in the mental health field, and perhaps the most momentum it has ever seen with expanding insurance coverage. The use of PGx testing in psychiatry is likely to increase as previous barriers (e.g., lack of education on the part of providers and patients, inconsistent reimbursement, and workflow issues) are reduced.
Does Your Medication Work for You?
Genomind’s leading pharmacogenetic testing and services are designed to help your clinician personalize your treatment plan based on your genetic profile. Learn more here.
Written in partnership with Dr. Jon Stevens, Chief of Outpatient Services and Child & Adolescent Psychiatry at The Menninger Clinic. This article originally appeared in Psychology Today.
