UBC researchers are exploring how genetic testing could better match patients with effective medications and improve depression care across B.C. and beyond.
Major depression is debilitating, painful and unfortunately common, affecting one in 10 Canadians. And while there are many antidepressant options available, finding one that is effective can involve a lengthy process of trial and error. That may soon change with the rise of pharmacogenomic testing that can provide information about how effective a drug will be, based on a person’s DNA.
More than half of patients do not respond to the antidepressant they are first prescribed, according to Dr. Jehannine (J9) Austin, professor of medical genetics and psychiatry at the UBC Faculty of Medicine, and Dr. Shahzad Ghanbarian, mathematical modeler at the Centre for Clinical Epidemiology and Evaluation, affiliated with UBC’s School of Population and Public Health.
The pair are part of a UBC research team exploring how pharmacogenomic testing could become part of routine depression care in British Columbia. Their work recently revealed that the testing could save B.C.’s public health system an estimated $956 million over 20 years by improving patient outcomes, preventing hospitalizations and reducing the need for more intensive treatments. Now, with new funding from Genome BC, they’re studying how best to roll it out.
Drs. Austin and Ghanbarian share how pharmacogenomic testing holds promise for faster, more effective depression treatment.
What is pharmacogenomic testing?
Dr. Austin: Pharmacogenomic testing is about taking a sample of saliva or blood, and looking at the DNA in it for genetic variations that influence how we metabolize the drugs that we might be prescribed. The way that we metabolize medicines is in part dictated by our genetics, and everybody’s genetics is a little bit different.
How can pharmacogenomic testing help someone experiencing clinical depression find the right antidepressant for them?
Dr. Austin: It’s not about doing a test and saying, “Aha, this is the one drug that you should use and these are the ones that you should not.” The results that you get would be more along the lines of, “Based on your genetic testing results, these ones would be more likely to work well for you, and these ones would be less likely to work well for you.”
Dr. Ghanbarian: Studies show that 40 to 60 per cent of patients do not respond to the first antidepressant they’re prescribed. And some can go through many trials to get to the effective medication. That’s a frustrating process for the patient and it’s also challenging for the prescribers. If we can find them effective antidepressant faster, we can reduce the number of patients with treatment-resistant depression, and cut costs to the health system, too.
1 in 10
Canadians will experience major depression in their lifetime.
1 in 2
Patients don’t respond to the first antidepressant they’re prescribed.
$956 million
Projected provincial health savings over 20 years with pharmacogenomic testing.
How can Canadians get access to pharmacogenomic testing for antidepressants?
Dr. Ghanbarian: A number of pharmacogenomic tests are available to patients in Canada through some pharmacies, benefits plans and direct-to-consumer online. Most require a requisition from a healthcare provider. They’re not currently publicly funded, so patients pay out of pocket. They cost from $300 to $2,500, although some may be covered by private insurance. It’s important to work with a healthcare provider in choosing which test to use.
Is pharmacogenomic testing available for other diseases or disorders?
Dr. Austin: Yes. It has been used in oncology and cardiology. When it comes to psychiatric conditions, there is the most data about using pharmacogenomics in treating major depression. However, the same principles apply for other conditions that are psychiatric in nature, such as anxiety or schizophrenia. You could use pharmacogenomic testing in the context of those conditions too. It’s just that we have a lot less data about its effectiveness.
Dr. J9 Austin consults with a patient.
What are the benefits of using pharmacogenomic testing for depression?
Dr. Ghanbarian: We found that the health system in B.C. alone could save an estimated $956 million over 20 years by providing pharmacogenomic testing for the treatment of moderate to severe major depression. Other provinces could see similar benefits. But there are also bigger savings on a societal level. Patients who have difficulty finding an effective treatment for their symptoms of depression not only deal with having side effects and disappointment. Some of them cannot work, or they lose their jobs, or need someone to take care of them. From an economic perspective, pharmacogenomic testing is a win-win scenario. Not only does it save the government money, but patients and society also benefit as well. Plus, getting people effective treatment faster will also save lives.
Could we see this testing become more widely available?
Dr. Austin: That’s what we’re studying next. Our data show that pharmacogenomic testing can help people and it can save the health system money, but what we don’t currently know how best to deliver it within B.C.’s public health system. So, we’re looking at different implementation strategies to determine what will best support patients and work for healthcare providers, while being cost-effective and feasible to bring into practice. We’ll be gathering a wide range of input from people with lived experience, health professionals and the public, with the hopes of providing policymakers with valuable guidance on how pharmacogenomic testing could be offered in B.C.
A version of this story was originally published on the UBC Faculty of Medicine website.
