Researchers in Montreal are working on tests that they hope could one day spot people on the brink of burnout, long before their work drains them of the last of their energy. And all it would take is a few samples of saliva and blood.

Patients suffering from burnout often appear exhausted, like they're sleepwalking through their day. They no longer care about their jobs, they're cynical or apathetic, and even moments that should be stressful no longer seem to affect them.

While burnout can happen to anyone, those in stressful "helping" professions are most at risk, such as paramedics, nurses, teachers and physicians.

As a psychological condition, "burnout" is still not well accepted by many in the mental health community and is often mistaken for clinical depression, which shares many of the same symptoms. But researchers are beginning to realize burnout is a distinct condition and that trying to treat a burned-out patient with medications for depression can actually backfire.

The key difference appears to lie in the stress hormone cortisol.

Cortisol helps us to wake up in the morning and, like adrenaline, is also released during periods of stress to give us a boost of energy.

In people with depression, cortisol levels tend to be high, since depression brings stress. But interestingly, cortisol levels in those suffering burnout tend to be low.

This has long puzzled mental health researchers since one would think that chronic stress would force the body to pump out more cortisol. Robert Paul Juster, of the Centre for Studies on Human Stress at Louis-H. Lafontaine Hospital in Montreal, admits this paradox is a bit of a mystery, but he says it's possible that the brains of those who are burned out might have already given up trying to manage stress.

"This is purely speculative, but it could be that cortisol levels shoot up in response to the stress initially, but they reach such a high level that the body and the brain sort of say, ‘Screw you, I'm shutting down.' And that's when you see the low levels," he tells CTVNews.ca, from Montreal.

Shutting down cortisol production might therefore be a defence mechanism, Juster explains.

Many with post-traumatic stress disorder also have low levels of cortisol, Juster notes, as do some of those suffering the chronic pain of fibromyalgia.

The problem with mistaking burnout for depression is that the antidepressants work by lowering cortisol. So in a person already suffering from low cortisol, antidepressants could actually worsen the problem.

That's why Juster, who's also a Ph.D. candidate in the Department of Neurology and Neurosurgery at McGill University, is part of a team that's working on a test that would spot the biological markers of burnout. The research is being funded in part from a $1-million donation from Bell to the Louis-H. Lafontaine Hospital Foundation.

The team is working on a simple spit test that doctors could offer patients to assess how their bodies are reacting to stress. Patients would fill out a questionnaire and then provide saliva samples throughout the day which would then be tested for abnormal levels of cortisol.

"What's great about a saliva test is that it's non-invasive and tests can be taken repeatedly throughout the day," Juster explains.

Juster says his team is now working on establishing what a normal or healthy level of cortisol is and how much it should fluctuate through the day. His team recently completed a study of 30 healthy workers from all kinds of professions, and then a sub-study of 88 health care workers, to try to pinpoint a healthy range.

Once that's complete, Juster and his team hope to be able to offer doctors a new tool for assessing how patients are handling chronic stress. The saliva test could act as a screening tool, and then a blood test would offer a clearer picture. His hope is that doctors would ask patients who appear under stress to undergo tests for cortisol along with their standards blood tests for high cholesterol, triglycerides and glucose.

Since all are affected by chronic stress, doctors could take all the scores together to create a profile of a patient's physical and mental health at the same time.

"We're trying to convince psychiatrists and physicians to look at these other biomarkers as well, which would then be an indication of their chronic stress," he says.

Spotting chronic stress in patients before they reach the point of burnout is important because both can take a toll on the body, Juster notes.

"Cortisol can infiltrate your whole body and it can alter the function of every cell in the body," he says.

Stress can cause high blood pressure and damage to the heart; it can also lower the immune response and put one at risk of infections and illnesses. And it's been tied to weight gain, diabetes, and miscarriage.

With the blood and saliva tests that Juster and his team are working on, doctors could more easily spot distressed patients at risk of burnout. Together, doctors could work with the patients to find ways to reduce or manage the patient's stress or make changes to their work lives, to set them on the road to recovery long before they burn out.