With genetic testing becoming more popular and accessible, many primary care providers wonder whether pharmacogenomic testing (analyzing DNA to understand medication response) is worthwhile when making treatment decisions for patients with mental health conditions.
REACH faculty member and clinical psychopharmacologist/psychiatric pharmacist Lynn Crismon, Pharm.D., FCCP, FASCP, DABCP, BCPP, says he is regularly asked about this topic. And while he wishes his answer was different, he emphasizes that “mental health is very complicated and complex.” Unlike oncology or cardiology, where genetic testing may help guide treatment, he explains, “Pharmacogenomic testing for mental health treatment is just not ready for prime time.”
We asked Dr. Crismon to describe the nuances of pharmacogenomic testing for children and adolescents and what PCPs should know about current research, clinical realities, and best practices.
The Appeal of Pharmacogenomic Testing
Genetic testing is being touted as “the cornerstone of personalized medicine,” offering individualized treatment recommendations based on a patient’s DNA, environment and lifestyle. And where pharmacogenomic testing is concerned, the hope is that this information can reduce the often difficult trial-and-error period of psychotropic treatment—minimizing side effects and accelerating symptom relief.
Pharmacogenomic testing is currently being used to guide medication selection for the treatment of certain cancers and heart disease, and many researchers believe that these rapidly evolving tests will soon have the ability to assist providers in choosing the best medication for a wider range of conditions.
Pharmacogenomic studies in adults with depression either show no difference in clinical outcomes compared with usual clinical care, or if they show improved outcomes with pharmacogenomic testing, the studies were not appropriately blinded to be able to make definite conclusions.
Only one study has examined pharmacogenomic testing in adolescents with depression, and it showed no difference in outcomes as compared with usual care.
What Pharmacogenomic Testing Can and Can’t Tell Clinicians
While pharmacogenomic testing is often marketed as a tool to help clinicians choose the “best” medication for mental health disorders, Dr. Crismon makes it very clear that it does not yet have this capability.
Pharmacogenomics tests can detect genetic variants in liver enzymes that influence how quickly or effectively a patient metabolizes certain drugs. Dr. Crismon explains that this information can help identify children who are poor metabolizers or ultra-rapid metabolizers. “If a child experiences adverse effects with every medication, we might suspect they’re a slow metabolizer; and in that case, genetic testing could be useful,” he says. Conversely, “If they don’t respond to any medications, that could point to ultra-rapid metabolism.”
While understanding medication metabolism can be useful in specific circumstances, Dr. Crismon cautions that at this time, there’s a lack of consistency among testing companies and how results are interpreted, which can lead to confusion and inconsistent clinical recommendations.
Ultimately, while pharmacogenomic testing can offer insights into metabolism, it doesn’t diagnose conditions or definitively predict which drugs will work best for a particular patient. “There’s no evidence that testing is better than good clinical care,” says Dr. Crismon.
Why Good Clinical Care Still Matters
As Dr. Crismon points out, there’s no substitute for quality holistic mental health care, where clinicians take things like environment, nutrition, sleep, exercise, nurturance, relationships, and co-occurring chronic illnesses into account.
For PCPs managing pediatric mental health, Dr. Crimson says the most effective approach remains:
- Careful clinical assessment and accurate diagnosis
- Attention to comorbidities
- Starting medications at low doses and titrating thoughtfully
- Close monitoring and follow-up
“These steps already account for metabolic variability and provide outcomes as good as expensive testing,” Dr. Crismon adds. “It’s not always easy, as anxiety and depression are close sisters, along with ADHD, so clinicians must take their time and tease out comorbidities.”
Bottom Line for Clinicians and Families
Pharmacogenomic testing is an exciting, quickly growing industry. It has become standard of care in oncology, but it is not currently ready for routine use in adults and youth with mental disorders. Dr. Crismon’s views align with the American Academy of Child & Adolescent Psychiatry (AACAP), which recommends avoiding pharmacogenetic testing to guide treatment in children and adolescents until there are “high-quality prospective studies to assess the clinical significance of pharmacodynamic and combinatorial pharmacogenomic testing” in this population.
As Dr. Crismon explains, “I do hope that one day it will be helpful, but there is no evidence it is helpful right now. Everyone wants a magic bullet, but nothing beats good holistic psychiatric care.”
Resources:
- The American Academy of Child & Adolescent Psychiatry (AACAP)’s statement on pharmacogenomic testing with brief context can be found here.
- For more information on pharmacogenomic testing in the treatment of depression, explore this comprehensive review.
