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According to a recent study, pharmacogenomic tests could help to choose the right treatments and the right dosage in case of depression.
Weight loss, dry mouth, drop in blood pressure, decreased libido… The undesirable effects of antidepressants are multiple. In an attempt to reduce them, researchers have analyzed the impact of pharmacogenomic tests on patients with depressive disorders. The goal? Enlighten health specialists on the proper use of these harmless drugs.
Pharmacogenomics: what is it?
Pharmacogenomics is the study of how genes affect the body’s response to drugs.
In this study, “The genes we tested aren’t actually linked to depression“says Dr. Oslin, a psychiatrist at Corporal Michael J. Crescenz VA Medical Center in Philadelphia.”They relate to how a person metabolizes drugs once they are in the body. Some of these genes will cause drugs to be metabolized much faster than normal. Others will cause the drugs to metabolize much slower than normal, meaning you’ll end up with a lot of drugs in your body.”.
The patients included in the study started or changed treatment with an antidepressant drug. The study included nearly 2,000 patients from 22 VA medical centers who were equally randomized, with half receiving pharmacogenomic testing and the other half receiving usual care. Oslin and his colleagues investigated whether genetic testing helped patients receive less medication and whether it produced better outcomes.
Part of them (966) underwent pharmacogenomic testing from the outset, while the other group (978) received usual care and had access to pharmacogenomic results after 24 weeks.
The interest of genetic tests on the choice of drugs
Having this information helps the doctor select the appropriate dosage for a specific patient. Patients in the control group underwent genetic testing, but their doctors did not see the results. This meant that doctors were making drug choices for their patients that were not supported by pharmacogenomic testing.
After 24 weeks of treatment, the group that underwent genetic testing experienced reduced symptoms of depression for up to 12 weeks.
“The group that underwent the genetic test showed better improvement in remission, response and improvement in symptoms”confirmed David Oslin, lead author of the study.
Towards a change in practices?
“The costs are actually very low because the results can be used throughout the patient’s life.”says Oslin. “So you’re not talking about a test that only has a lifespan of five minutes. And there’s really no risk in taking the test. You just got the mouth swab or a blood test. The cost is low, risk is low, and benefits to the general population are likely small. But overall, this test likely benefits some patients significantly.”.
Despite these first positive results, the group of scientists wishes to remain cautious:
“We wouldn’t say the study is robust enough to recommend testing everyone (…) But I believe that these results (…) although weak, will encourage doctors to test patients and obtain this genetic information Dr. Oslin revealed.
It also clarifies that future work “need to explore subgroups of patients who would benefit most from testing”.
Depression: possible treatments
There are many treatments for depression. The management varies according to the severity of the symptoms and the origins of the latter. The treatment must also be adapted to the needs of the patient. Among the most common are:
- psychotherapeutic support;
- Antidepressant drugs;
- Hospitalization (reserved for cases where the risk of suicide is real).
The success of the treatment depends on many factors: a healthy lifestyle, the personal commitment and the will of the depressed person, the support of relatives, the relationship with the therapist…