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Genetic Testing for Better Depression Treatment

Why Cytochrome p450 is a phrase you should know.

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Personalized medicine is the unique tailoring of medical treatment to a patient’s individual symptoms AND their genetic profiles. What was once thought of as science fiction is no longer a fantasy - it's here and it offers enormous potential to manage diseases, particularly mental illness.

I have been recommending personalized medicine, particularly the genetic testing of Cytochrome p450, for patients who are considering antidepressants for treatment of depression or who've had treatment resistant depression. As a professor and practicing psychologist, I know that this simple cheek swab test can help identify what medications work best for you – and which ones to avoid.

The results gained from getting this test can minimize dangerous adverse drug interactions, side-step side effects and offer greater confidence taking medication. What is perhaps the most amazing aspect of this kind of personalized test is that it will significantly reduce the time and prolonged anguish of finding symptom relief by pinpointing which antidepressant medication, and what dosages, may be treatment productive. For many who have languished for years trying to find medications that work, endured terrible side effects or experienced adverse reactions, this test is life-changing.

The problem, however, has been getting patients to know that this test is out there. And finding physicians who understand what this genetic test does.

Though I live in New York City, a mecca of progressive healthcare and research, my patients have a tremendously difficult time finding a physician or nurse practitioner who understands the benefits of this test. While there may be many in the medical field who utilize this genetic test, the majority seem unfamiliar with Cytochrome p450 tests. Some shunned it, believing that test wasn’t useful or was an unmanageably high “out of pocket” expense to pursue. Others weren’t aware that Cytochrome p450 testing is fully covered by Medicare and that many insurance companies cover the genetic panel.

Through my experiences reading about why this ignorance existed, I came upon research that calls this lack of awareness "genetic illiteracy" – where many in the field of medicine, as well as health care insurers, have a hard time keeping up with genetic tests that are now available.

Regardless of the whys, Cytochrome p450 testing needs more mainstream notice. Its usefulness is enormously far reaching.

What Cytochrome p450 Testing Provides

Most who live with depression generally find their treatment journey including the use of antidepressants. This genetic panel of tests helps evaluate your scientific pairing with the medication you're taking - and looks at two vital issues. The first of which is to identify what kind of metabolism for medications you genetically possess. There are four metabolizing categories: poor, intermediate, extensive, and ultrarapid. Discovering what kind of "metabolizer" you are will help steer your antidepressant treatment.

Let’s look at these in more detail.

  • A poor metabolizer (PM) is a person whose metabolism takes in the medication very slowly, resulting in increased levels of the medicine in the bloodstream. This sluggish process causes significant side effects, and poses toxicity risks such as serotonin syndrome—a potentially life-threatening condition caused by toxic levels of serotonin. If you’re a poor metabolizer, you not only have the hardship of experiencing side effects and toxicity, you also continue to have depressive symptoms.
  • An intermediate metabolizer (IM) is a person whose metabolism of a drug occurs at a slower rate than normal. People in this category experience side effects and mild toxicity but not as intensely as do poor metabolizers. As you might expect, medication success is guarded in this category. You notice some symptom relief, but it won’t be substantial.
  • Extensive metabolizers (EM) have an average expected range for metabolism. Herein, you absorb medication effectively and are able to experience symptom relief with little or no side effects.
  • Ultrarapid metabolizers (UM) quickly process medication, rendering drug treatment virtually ineffective. Because your genetic metabolism synthesizes the medication too fast, you cannot experience its therapeutic effects. If you’re an ultrarapid metabolizer, you feel no symptom relief whatsoever.

Many who live with mental illness are vulnerable to other medical issues, sometimes taking more than one medication. The second component of this test allows you to understand how your other medications affect you, and evaluate if you are at risk for an adverse drug reaction (ADR). Adverse drug reactions are frequently serious, some resulting in ototoxicity, requiring admission to hospital, and in rare instances, death. If you are at risk, your physicians will prescribe more genetically friendly medicines.

Tips for Obtaining Cytochrome p450 Testing

Being informed, educated and ready is the goal. This is what I suggest to patients when seeking this genetic test.

1) Call your insurance carrier and ask them what the coverage is for Cytochrome p450 testing. Generally, the testing panel carries the CPT codes 81225, 81226 and 81227.

2) Be patient as you talk to the claim representative. Chances are he/she may not be aware of this test. If necessary, ask to speak to a supervisor.

3) Then ask what lab provides this service. Get the name of the lab, the address and the phone number.

4) You may be able to go out of network and choose a lab of your own. If you do this, find out what your deductible is and what the insurance company consider customary as a fee.

5) If you choose to find a lab of your own, be sure to do a thorough checking of the lab, how long they have been providing this genetic test, etc. Many genetic labs can send you pamphlets and information about Personalized Genetic Tests. Whether you choose to seek an out of network lab or go with one assigned by your insurance, you can give the information to your physician to help educate him or her about the procedure.

6) Call the lab and ask how they obtain the genetic material. Some labs will send you a prepackaged swab kit, while others will want you to come in and have the test done there.

7) When you meet with your physician, nurse practitioner or psychiatrist, have the CPT codes, the lab and any other information to help make the recommendation for this test easier.

Using Your Results

When your test results arrive from the lab to your prescribing doctor's office, it's important to schedule a meeting to go over the results. This is not something that can be delivered with a cursory phone call from the doctor's office. The labwork will detail many issues and I encourage you to ask for a copy of the report for your own records. You and your doctor will make decisions about your antidepressant medication, the dosage and possible changes of your "other" medications. The genetic indicators will also be used to help prescribe future medications.

Living with a mental illness can be challenging, but utilizing personalized medicine can offer answers that heretofore weren't possible. It is a field of healthcare that brings hope and possibility along with its hard science.


Alarcon, R. D. (2009). Pharmacogenomic perspectives on the management of mood disorders. The Psychiatrist, 33, 361–363.

Carroll, J. (2007). Biogenetic tests emerge from their chrysalis. Biotechnology Healthcare, 4(5):37-44.

Gillman, P. K. (2009). Serotonin syndrome: History and risks. Fundamental and Clinical Pharmacology, 12(5), 482–491.

Mrazek, D. A. (2006). Psychiatric pharmacogenomics. Focus, 4, 339–343.

Penas-Lledo, E.M. et. Al (2013). CYP2D6 ultrarapid metabolism and early dropout from fluoxetine or amitriptyline monotherapy treatment in major depressive patients. Molecular Psychiatry, 18, 8-9.

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