The way you respond to a medication is affected by many factors, including but not limited to your age, health history, environment, and unique genetic profile. Some of these factors may be, at least in part, characterized by your ethnicity or ancestry. This is the foundation of ethnopsychopharmacology.
What is ethnopsychopharmacology?
Ethnopsychopharmacology is a field of study seeking to understand ethnic differences in the use and efficacy of psychiatric drugs. Ethnopsychopharmacology examines these differences, as well as factors that may drive these differences.
For the purpose of this article, we will explore the genetic component of ethnopsychopharmacology.
While your exact genetic makeup is your own, individuals who can trace their ancestry to particular ethnic groups or geographic regions often have common genetic variations. From pharmacogenetics (PGx), we know about the relationship between drug response and your DNA. Genetic variations common in specific ethnic populations have been associated with differences in treatment response. What that means: Your ethnicity may have surprising effects on how mental health medications work for you.
Science still does not fully understand why some ethnicities may be affected by a particular genetic variant. However, researchers know that understanding genetic differences in how people break down or may respond to mental health medications can provide powerful information to a prescribing clinician. (Just see how genetic testing for medication response can transform mental health treatment.)
Ethnopsychopharmacology in practice
It is clear that certain genetic variants occur more frequently in some ancestry groups than others. Also, the same genetic variation can have different implications for different ancestries.
Since many of these DNA differences can significantly impact your ability to metabolize (break down) medications, we should consider this information when prescribing. In response, a few pharmacogenetic tests have provided specific recommendations for various ethnic groups.
With insights from ethnopsychopharmacology, clinicians can make more thoughtful prescribing decisions.
Here are two examples of ethnopsychopharmacology, plus how you can personalize your medication plan.
How does the CYP2C19*35 variant affect mental health treatment?
The CYP2C19*35 variant almost exclusively impacts people of African ancestry. Normally, this gene variant travels along with a partner variant called *2, but in those of African ancestry, it can exist by itself. Historically, few consumer genetic panels have tested for the *35 variant because the assumption was that testing for the *2 variant alone was sufficient.
An individual who carries the *35 variant in the CYP2C19 gene will have markedly reduced function of an enzyme that is involved in the metabolism of several medications. That means more of the medication will stay in the body, which can lead to side effects.
Someone who is a “CYP2C19 poor metabolizer” may experience side effects with common selective serotonin reuptake inhibitors (SSRIs), including:
- Citalopram (Celexa)
- Escitalopram (Lexapro)
- Sertraline (Zoloft)
The *35 variant can also affect how the body handles other types of antidepressants and anti-anxiety drugs.
How can clinicians adjust treatment for the CYP2C19*35 variant?
If clinicians know a patient has the *35 variant, they may wish to use a lower starting dose for select SSRIs, as recommended by the Clinical Pharmacogenetics Implementation Consortium, or they can choose an alternative medication.
How does the HLA-B*15:02 variant affect mental health treatment?
The HLA-B*15:02 variant is found in 4 to 7 percent of people of East, South, or Central Asian or Oceanian ancestry. It is rarely found in people of African or Middle Eastern ancestry.
An individual who carries the *15:02 variant in the HLA-B gene is at higher risk of a serious adverse skin reaction to carbamazepine (Tegretol), which is often prescribed to treat bipolar disorder.
Seema Patel, PharmD, BCPP, a Medical Science Liaison at Genomind and a person of South Asian ancestry, had no idea she carried the variant until she had her own PGx test done. “If I had ever taken certain medications that are affected by this variant, like Tegretol, I would have risked my life, since they can cause serious skin reactions that may require hospitalization or even be fatal,” she said.
How can clinicians adjust treatment for the HLA-B*15:02 variant?
For patients of Asian ancestry, clinicians will typically order a test to check for this variant before prescribing carbamazepine.
How to personalize your mental health treatment by your ethnicity
Wondering if you have these ethnicity-related variants or other genetic factors that can affect how your body works with mental health medications?
Genomind’s pharmacogenetic test evaluates 24 genes related to mental health treatment, including the variants mentioned above. Genomind’s test and services provide guidance across 10+ mental health conditions and over 99% of the most commonly-prescribed medications to help your clinician determine:
- Which medications may be more or less likely to be effective at relieving symptoms
- Which medications may be more or less likely to produce side effects
- How you metabolize medications
These insights from pharmacogenetic testing allow your clinician to make more-informed drug selection and dosing decisions, personalized to you.
Genomind’s PGx report is unique in that it highlights specific recommendations for various ethnic groups. The panel includes gene targets of historically underserved populations.
For example, most PGx tests don’t look for the CYP2C19*35 variant. But when recent scientific guidelines recommended adding it, Genomind did. As a result, more than 100 individuals with this variation learned about it with the Genomind test—and their clinicians were able to make more informed decisions about medication.
Incorporating ethnopsychopharmacology data like the examples above is another way to help you and your clinician better understand your unique makeup, and in turn, personalize your prescription.
On a broader scale, the safety implications of considering ethnic factors like the CYP2C19*35 and HLA-B*15:02 gene variants warrant further research of pharmacogenetics diversity amongst more populations and geographic regions.
