Antidepressants can be life-changing for people with major depression, but it can be a long and difficult road to find the right drug. Many medications take six to eight weeks to have an effect, and up to half of patients wait that long only to learn that the medication doesn’t work for them or causes intolerable side effects. While there are many medication options available, each one takes time to reveal its benefits or lack thereof.
A new psychotropic genetic test, however, may shorten that road and reduce side effects, too. A study presented at the American Psychiatric Association Annual Meeting in May found that using the GeneSight (Myriad Genetics) test to help choose a medication made patients 30 percent more likely to respond to antidepressant treatment and 50 percent more likely to achieve remission.
MIND & MEMORY NEWSBRIEF
Air Pollution and Dementia Appear to Be Linked
Researchers in London found that people who live in areas with high levels of nitrogen dioxide in the air may have a 40 percent higher risk of being diagnosed with dementia than people who live in areas with the lowest levels of nitrogen dioxide. The researchers used health records to track 131,000 patients between the ages of 50 to 79 and used their ZIP codes to estimate their annual exposure to air pollution. This was an observational study, so it can show only a relationship but not causation.
The Test. For patients, the test is nothing more than a cheek swab. The magic happens in the lab, where the company analyzes how a patient’s genes may affect his or her response to medications commonly prescribed to treat depression, anxiety, bipolar disorder, post-traumatic stress disorder, and other behavioral health conditions. Within a couple of days, the company gives the physician a chart that categorizes medications into three categories: green for medications with no known gene-drug interaction, yellow for medications with a moderate gene-drug interaction, and red for those with a significant risk of treatment failure or side effects. The report also notes when a standard dose should be raised or lowered based on the person’s DNA.
The Study. In a study of 1,167 patients with moderate to severe treatment-resistant depression, researchers compared patients who were prescribed medications that were chosen using the genetic test results with a control group of patients who were prescribed medications without reviewing genetic information. All patients had experienced at least one medication failure, and most had experienced at least three.
At the eight-week mark, improvements in rates of response and remission were significantly greater in the genetic guided-care group than in the control group. Those rates continued to improve through week 24.
At the beginning of the study, 213 patients were taking medications that were determined to be poor genetic matches. Switching those patients to medications that GeneSight identified as genetically congruent led to significant improvement. In that subset of patients, symptom improvement rose from 21 to 34 percent, response rate rose from 17 to 29 percent, and remission rose from 9 to 22 percent.
What You Need to Know. Approximately 23,000 physicians in the United States are currently using GeneSight, according to Myriad Genetics. Medicare and Medicaid cover the cost of the test, the company notes, and people with commercial insurance usually pay less than $330.
THE VIEW FROM DUKE
An Idea Before Its Time
“The American Psychiatric Association Task Force for Novel Biomarkers and Treatments recently deliberated on pharmacogenomic platforms (such as GeneSight) and their ability to guide psychiatric treatments. This has been long sought after in psychiatry, and many believe that it may be a feasible approach as science continues to advance within the next five to 10 years, but the task force felt that there was insufficient data to support widespread use of pharmacogenomics to guide treatment practices at this time. Notably, this report occurred just prior to the presentation of the GeneSight poster data. GeneSight does appear to have one of the most advanced platforms in the pharmacogenetics market and, in some patients, this test is covered by insurance, making it appealing. But the recent data, although encouraging, still do not provide convincing support for its widespread application. The algorithms used for GeneSight’s recommendations are unknown and the methodological shortcomings of these studies and the need for increased research does not justify the cost of these tests at this time for most patients.”
STEVEN SZABO, MD,
Assistant Professor of
Psychiatry and Behavioral Sciences,
School of Medicine
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