DEPRESSION TESTING
Info may help pinpoint treatment
A research team from the University of Saskatchewan is developing a blood test that could help identify different kinds of depression.
A finger-prick blood test could help doctors choose more effective treatments for depression, University of Saskatchewan researchers propose.
In a step toward personalized medicine, the Saskatoon-based investigators say they hope to one day develop and sell test kits for doctors to quickly determine if antidepressants would work for a patient.
“What we’re trying to do is change the way depression is treated,” says Prof. Lisa Kalynchuk of the U of S department of medicine.
One in five Canadians will have a mental illness in their lifetime, the Canadian Mental Health Association says.
Antidepressants currently on the market don’t work well for about half of patients diagnosed with depression, Kalynchuk said.
Meanwhile, the person shuttles back and forth to the doctor to try different medications and drug combinations — a trial-and-error approach that can take months and leave patients frustrated.
“It’s not an evidence-based way to design a course of treatment,” she said.
Many of these medications change the way the brain processes a chemical signal called serotonin.
Mindful of the connection between depression and the immune system, pharmacy Prof. Hector Caruncho looked at the proteins in white blood cells that recognize and move serotonin.
When his team examined the cells from 40 people newly diagnosed with depression, the researchers found two distinct groups based on the pattern of the proteins clumped together.
Patients with protein gathered in fewer, larger clumps were more likely to get relief from antidepressants than people whose proteins were grouped into smaller, more plentiful groups. They have previously published the results in the Journal of Affective Disorders.
“You come into your doctor’s office. You get diagnosed with depression. You give a blood sample. The next day the doctor can know which (category) you fit into,” Kalynchuk.
If the result suggests antidepressants are unlikely to work, the doctor could try prescribing a mood stabilizer, anti-anxiety drug or behavioural therapy, Kalynchuk said.
The finding also opens the door for potential development of new types of drugs to treat depression, Caruncho said.
Since the first study was done on a relatively small group of people in Spain, collaborators are attempting to reproduce the results in a larger group of people in Canada and the U.S.
There are other groups looking for evidence of different types of depression.
A blood test that looked at nine genetic markers in people with depression could also help predict which patients feel better with talk therapy, found a separate Chicago-based study published last year.
The Canadian Biomarker Integration Network in Depression (CAN-BIND) has also brought together scientists aiming to find signs that would allow them to group depression into subtypes.
There are other signals involved with mental illnesses, such as norepinephrine and dopamine.
Caruncho and Kalynchuk also want to peer at white blood cells to see whether there are differences in the distribution of the proteins that deal with those chemical signals, too.
Identifying subtypes of depression that respond to different treatments should help change the perception that people can snap out of depression purely by willpower, Caruncho said.
“Remember, they are sick people — like diabetes, or stroke, which all of us can have,” Caruncho said.