Personalized Pharmacogenomic Treatments Offer Improved Outcomes for Major Depression, Study Shows

Pharmacogenetic treatments for psychiatric illnesses are becoming more prevalent as research builds on the benefits it offers

Comments on pharmacogenomics and pharmacogenetics in psychiatry. James Kennedy, MD, Head of Molecular Science and Head of the Tanenbaum Center for Pharmacogenetics at CAMH and Professor in the Department of Psychiatry and Institute of Medical Science at the University of Toronto.
“Using pharmacogenetics for treatment-resistant depression we can be much more precise about exactly which drug will suit each person’s unique blueprints for the bodily systems that usher the drug into the brain and enable it to fight depression,” explained James Kennedy, MD (above), a molecular scientist and pharmacogenetics expert at the University of Toronto, where a one-year study of pharmacogenomics in psychiatry recently concluded. Such personalized treatments are a core tenet of precision medicine. (Photo: Center for Addiction and Mental Health)

Treatment-resistant depression (TRD) is twice as likely to be successfully treated when personalized treatment is guided by pharmacogenomics, according to a study conducted at the Center for Addiction and Mental Health (CAMH). This is yet another study demonstrating the benefits precision medicine offers healthcare providers for treating patients with difficult to treat conditions.

Researchers from CAMH, a psychiatric teaching hospital in Ontario, Canada, performed their one-year study on about 300 patients with TRD. The condition is characterized by persistent depression after attempting treatment using at least two antidepressants. The study used a double-blind, randomized research model to test and treat patients using pharmacogenomic testing. 

Testing samples taken from cheek swabs, the researchers determined both the best drug for each patient and the dose that was ideal for his/her unique genetic makeup. Medications projected to work fastest and with the fewest side effects were ultimately selected for each patient.

The CAMH researchers published their findings in Translational Psychiatry, titled, “Clinical Utility of Combinatorial Pharmacogenomic Testing in Depression: A Canadian patient- and rater-blinded, randomized, controlled trial.”

Pharmacogenetic Testing Doubles Rate of Remission

The results from the CAMH study were impressive. Patients who underwent personalized pharmacogenomic-guided treatment experienced nearly double the rate of remission when compared to the control group. 

“Remission—or full recovery from symptoms—is one of the most challenging endpoints to achieve when treating major depressive disorder,” said neuropsychiatrist James Kennedy, MD, senior author of the CAMH study in a news release. Kennedy is Head of Molecular Science and Head of the Tanenbaum Center for Pharmacogenetics in the Campbell Family Mental Health Research Institute at CAMH. He also is Professor in the Department of Psychiatry and Institute of Medical Science at the University of Toronto.

“The findings from this study contribute the first randomized, controlled data in Canada to the growing body of evidence of the clinical value of combined multi-gene pharmacogenetic testing,” he noted.

Not only does the CAMH study emphasize the benefits pharmacogenomic treatments offer, but it also illustrates how personalized medical treatments improved patient outcomes in general. 

Canadian Health Plans Do Not Cover Pharmacogenomic Treatments

While personalized treatments are becoming increasingly recognized as a superior method of treating a variety of conditions, healthcare infrastructure has been slow to adjust to these advances. Kennedy highlighted how Canadian public health plans lacked coverage for pharmacogenetic testing in spite of the cost benefits that these tests offer.

“Pharmacogenetic tests are currently not covered by public health plans in Canada,” Kennedy said. “The average healthcare savings following pharmacogenetic testing, per depression patient, are over $3,000. If half of the 1.6 million Canadians with depression could get the test, savings could total $2.4 billion per year. Patient suffering during trial-and-error prescribing would be reduced. These study findings should be considered by health policy decision makers, as they provide further impetus for implementation of reimbursement by public payers.”

Other Research Focusing on Pharmacogenomics

CAMH is by no means the only institution recognizing the benefits of pharmacogenomics for patients with psychiatric illnesses. Other institutions also are exploring how to leverage pharmacogenetic testing for this specific population.

One example of other research into pharmacogenetic treatments for mental illnesses is a recently announced collaboration between mental healthcare provider Prairie Health and the University of Western Australia (UWA). The joint effort is focused on learning how genetics impacts treatments for anxiety disorders. 

Previous research by Prairie Health found that two thirds of patients seeking psychiatric treatment had previously been prescribed medications that would not have been used if their genetic makeup had been known.

“Choosing medications matched to a patient’s profile can improve their experience by reducing side effects and producing a faster time to treatment response,” said Sean Hood, MMBS, Head of UWA’s School of Psychiatry and lead researcher on the new collaboration. 

With personalized pharmacogenomic treatments increasingly being shown to be more effective than traditional psychiatric treatments, mental healthcare providers will want to keep an eye on this emerging trend. As prescribing routine treatments becomes increasingly based on genetic testing, integrating pharmacogenomic testing into clinical workflows will create more opportunity for improving patient outcomes.  

—Caleb Williams

Related Information:

Pharmacogenetic Testing Shows Promise Improving Symptoms in Patients with Treatment-Resistant Depression

Clinical Utility of Combinatorial Pharmacogenomic Testing in Depression: A Canadian patient- and rater-blinded, randomized, controlled trial

Prairie Health and UWA Collaborate to Accelerate Precision Psychiatry

James Kennedy, MD

Sean Hood, MMBS

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