How Genetic Testing is Changing Depression Treatment

Traditionally, treatment decisions have been based on subjective factors, such as what has worked for other patients. A doctor often will prescribe a medication they’ve had success with and tell a patient to try it for eight weeks. If the patient doesn’t improve, the doctor may try three different things:

• Adjust the dose.
• Add another medication.
• Discontinue that medication and try another.

If someone suffers from depression, the last thing they want to go through is a lengthy trial-and-error process with multiple medications. The process can be frustrating and leave them feeling worse, not better. Enter genetic testing:

Genetic Testing & Treatment

One of the biggest challenges in treating depression is that doctors have had few objectives, evidence-based factors to guide them to the medication appropriate for an individual patient.

Pharmacogenomics, a type of personalized medicine that uses a patient’s DNA to guide medication treatment decisions, is rapidly changing that. It answers the question of why some medications may work better with a unique genetic profile and some medicines might not work at all.

Everyone’s metabolism is different. Your genes can affect how quickly your body breaks down (or metabolizes) medicine. For example, if you are a rapid metabolizer of a medication, the medication is rapidly broken down and may be removed from your system too quickly to provide symptom relief.

On the other end of the spectrum, if you are a slow metabolizer of a medication, it may stay in your system longer than needed and you may experience unwanted side effects.

A healthcare professional like a primary care doctor, psychiatrist, or psychiatric nurse practitioner can order a test that provides this kind of genetic insight. One example is the GeneSight test, which analyzes your DNA to predict how you may respond to certain medications.

The report divides medications into three categories (green/yellow/red) to help your doctor get a better understanding of which medications may be more likely to work for you and which may require dose adjustments, may be less likely to work or may have an increased risk of side effects based on your unique genetic makeup.

Research Shows Genetic Testing Effectiveness

This kind of genetic testing is backed by scientific data. In January 2019, the Journal of Psychiatric Research published findings from the largest-ever pharmacogenomics depression trial called the GUIDED study.

This 24-week study included nearly 1,200 patients with moderate-to-very severe depression who had failed at least one psychotropic medication. The study was conducted at 20 academic sites (including hospitals like Mass General and Stanford) and 40 community sites. The National Network of Depression Centers (NNDC) and its founding chair Dr. John Greden worked on both the design and execution of the study.

The study showed that patients with a major depressive disorder who had failed at least one psychotropic medication had a 50% improvement in remission rate and a 30% increase in response rate when their medication selection was guided by the GeneSight test compared to unguided treatment as usual.

And the test offers hope for patients who need it most. Those patients who entered the study on a red category medication saw a 153% improvement in remission when switched to a green or yellow category medication by week eight compared to those who remained on red category medications.

In addition to the GUIDED study, another study published in Current Medical Research and Opinion showed that getting on the right medication can help financially as well. Patients who received GeneSight testing saved $1,036 in total annual medication costs compared to treatment-as-usual patients.

The studies confirm there is a better way to help patients get on the road to mental wellness faster by eliminating painful, frustrating trial and error.

-Biz Journal

In conclusion, genetic testing:

• Is usually covered by insurance
• Simple, just a swab in the cheek
• Quick, results usually take a few days
• Testing only needs to be done once per lifetime
• However, there is uncertainty about the use of GeneSight Psychotropic pharmacogenomic genetic panel to guide medication selection. It was associated with improvements in some patient outcomes, but not others. (-NIMH) Therefore, it may also simply be another tool that can help with treatment and hopefully the lessen symptoms.

References & Information

• How Genetic Testing is Changing Depression Treatment by Biz Journal
  
• Read more about Genetics

National Ints. of Mental Health: Health Quality Ontario (2017). Pharmacogenomic Testing for Psychotropic Medication Selection: A Systematic Review of the Assurex GeneSight Psychotropic Test. Ontario health technology assessment series, 17(4), 1–39.