Genetic testing could help patients with depression: UBC study

Targeted genetic testing could help avoid trial and error as doctors look for the best treatments for patients with depression

Article content

New research from the University of B.C. shows that a type of genetic testing could benefit patients with depression, and aid physicians in prescribing the most effective medications.

The bottom line could be better outcomes for patients with major depressive disorders, and substantial savings for provincial health, said Dr. Shahzad Ghanbarian, lead author of the study and a researcher and health economist at UBC’s centre for clinical epidemiology and evaluation.

Advertisement 2

Article content

Article content

Linda Riches, 67, was one of three patients who took part in the study, was prescribed at least a dozen antidepressants, starting in her 30s, but they failed to help. Her depression affected her work as a teacher, and her family life. Years went by before one medication turned out to be the right fit.

“If you’ve been off because of a mental health issue, people just don’t want to talk about it. So they ignore it. Nobody wants to come and say, ‘Is there anything I can do to help you?’” she said from her home near Prince George.

depression genetic testing
Linda Riches tried at least 12 different antidepressants before one worked for her, but she says DNA testing that is publicly funded could help alleviate that type of trial-and-error process so people don’t have to keep struggling while trying so many medications that don’t work for them. Photo by Handout /The Canadian Press

Only 40 to 60 per cent of patients respond to the antidepressant initially prescribed, said Ghanbarian.

“Around 27 per cent of patients experience side effects they can’t tolerate, including side effects that lead to hospitalization. If their condition wont get better, they try another one, and another one. Eventually they may give up. It’s frustrating for the patient, and challenging for the prescriber,” said Ghanbarian.

According to the study published in the Canadian Medical Association Journal, pharmacogenomic testing, which analyzes how your body metabolizes medications, could save the health system $956 million over 20 years.

Article content

Advertisement 3

Article content

“Until now, there has been a lack of evidence in terms of cost effectiveness. This is comprehensive data,” said Ghanbarian. The study used mathematical modelling to look at 200,000 simulated patients.

Dr. Shahzad Ghanbarian
Dr. Shahzad Ghanbarian is a researcher and health economist at UBC’s centre for clinical epidemiology and evaluation. Photo by Handout

The data suggests pharmacogenic-guided treatment is associated with a 37-per-cent reduction in treatment-resistant depression.It could also save patients the process of trial and error as they work with their treatment provider to get symptoms under control.

“A unique element of our model is that it is drug-specific, thereby incorporating most prescribed antidepressants in Canada,” said Ghanbarian, who recently presented the findings at the International Congress of the EuropeanSociety of Pharmacogenomics.

Pharmecogenomic testing, uses a simple saliva test, or cheek swab to look for genes that determine how a person metabolizes a specific medication, and can help determine more precise dosages.

Based on the genetic profile, it would be easy to see if the patient has a genetic predisposition to metabolize quickly or slowly, whether the  the concentration of a medication in the body could be higher or lower, said Ghanbarian.

Advertisement 4

Article content

The testing is already in use in some jurisdictions for a variety of illnesses to determine the likelihood of a medication working or causing serious side effects, including Tamoxifen for breast cancer, Abacavir for HIV, and some blood thinners.

Pharmacogenomics testing in B.C. is not covered by the public health system, but is available commercially.

On their website, the Ministry of Health said they are examining clinical adoption of the testing, and looking at its economic benefits and utility.

The World Health Organization estimates that five per cent of the global population suffer from depressive disorder, and it is the leading contributing factor to disability worldwide. One out of 10 Canadians will experience depression in their lifetime.

[email protected]

— with files from CP

Bookmark our website and support our journalism: Don’t miss the news you need to know — add and to your bookmarks and sign up for our newsletters here.

You can also support our journalism by becoming a digital subscriber: For just $14 a month, you can get unlimited, ad-lite access to The Vancouver Sun, The Province, National Post and 13 other Canadian news sites. Support us by subscribing today: The Vancouver Sun | The Province.

Related Stories

For more health news and content around diseases, conditions, wellness, healthy living, drugs, treatments and more, head to – a member of the Postmedia Network.

Article content


Postmedia is committed to maintaining a lively but civil forum for discussion and encourage all readers to share their views on our articles. Comments may take up to an hour for moderation before appearing on the site. We ask you to keep your comments relevant and respectful. We have enabled email notifications—you will now receive an email if you receive a reply to your comment, there is an update to a comment thread you follow or if a user you follow comments. Visit our Community Guidelines for more information and details on how to adjust your email settings.

Originally posted 2023-11-21 14:00:32.