Treatment-resistant depression can be a frustrating challenge for doctor and patient alike. The trial-and-error process of trying different medications and treatments to see what alleviates patients’ depression symptoms can feel like a “shot in the dark” approach.

According to Ann McDonald, former editor of the Harvard Mental Health Letter, in her blog post on the Harvard Health Blog, only about a third of patients who are diagnosed with major depressive disorder (MDD) find a medication that works for them on the first try.

“When the first medication doesn’t adequately relieve symptoms, next step options include taking a new drug along with the first, or switching to another drug. With time and persistence, nearly seven in 10 adults with major depression eventually find a treatment that works. Of course, that also means that the remaining one-third of people with major depression cannot achieve remission even after trying multiple options.” 

The Mayo Clinic says: “If you’ve already tried an antidepressant and it didn’t work, don’t lose hope. You and your doctor simply may not have found the right dose, medication or combination of medications that works for you.” One way to find out this information is through pharmacogenomic testing, which analyzes your genes and tells your doctor what might work best for you.

Why is it that some patients find relief sooner and others experience treatment-resistant depression?  Let’s look at some of the aspects.

How to Recognize Treatment-Resistant Depression Factors

The most obvious factor that a patient is experiencing treatment-resistant depression is the patient’s lack of response to antidepressants.  However, according to Psychiatric Times, there are other factors that predispose a patient to treatment-resistant depression. These can include:

• The duration of major depressive episodes. According to the article, “the longer the episode of depression, the greater the atrophy in specific brain regions (e.g., hippocampus); the cognitive and behavioral changes that take place during long episodes make a return to previous well-being difficult
• How severely the patient suffers from the depressive episode. This can be on both ends of the spectrum from a mild to a major episode.
• Melancholic features. “Treatment-resistant depression is more prevalent in bipolar depression than in MDD; the specific investigation of subthreshold manic symptoms is pivotal,” according to Psychiatric Times.
• Comorbidity. The presence of other diseases can cause a patient to be more susceptible to treatment-resistant depression – especially, generalized anxiety order.
• The patient’s age. It appears that elderly patients may be more predisposed to treatment-resistant depression.

A patient’s biology and genetics can also be factors in treatment-resistant depression, and more research must be conducted to determine what role these things play.

However, genes can play an important role in developing a plan that can help with your specific treatment-resistant depression through pharmacogenomic testing.

How Pharmacogenomics Can Help

Pharmacogenomics studies the genetic makeup of patients to determine how they might respond to medications. These tests uncover whether patients are producing enzymes to effectively break down or use medication compounds and how well their bodies will excrete them. They also evaluate some genes which predict efficacy and/or side effects with certain medication classes.

The combinatorial, multi-gene GeneSight Pharmacogenomic test has been found to better predict antidepressant treatment outcomes for patients with depression, and their use of health care resources, than any of the individual genes that comprise the test, according to a peer-reviewed analysis by investigators from the Mayo Clinic and Assurex Health, and published online by The Pharmacogenomics Journal. ¹

GeneSight® Psychotropic uses a proprietary algorithm to analyze 12 different genes to weigh their combined influence on patient response to 64 psychotropic medications. In clinical studies published in peer-reviewed journals, using the GeneSight Psychotropic test has been shown to reduce symptoms of depression by 70% and double a patient’s odds of response and remission compared to treatment as usual.²

Options to Consider for Treatment-Resistant Depression

Using results of the GeneSight test, physicians can better determine which antidepressant medications may work with patients suffering from treatment-resistant depression. Additionally, integrated therapeutic strategies, somatic therapy and deep brain stimulation may be helpful to treatment-resistant depression patients.

Ending the costly and exhausting trial-and-error process for treating treatment-resistant depression can be a welcome relief for doctors and patients alike.

¹ Altar, CA, et al. (2015) Combinatorial pharmacogenomics predicts antidepressant responses and healthcare utilizations better than single gene phenotypes. Pharmacogenomics J advance online publication, February 17, 2015; doi:10.1038/tpj.2014.85.

² La Crosse Clinical Study, October 2013