A team of Russian scientists discovered an easier way to analyze stress levels and, in turn, determine the body’s ability to deal with depression. By measuring the concentration of the hormone cortisol in individual strands of hair, researchers determined a person’s ability to respond to stress, according to a study published Tuesday in the journal Metabolic Brain Disease.

Cortisol levels are typically measured through blood tests, which are often inconvenient and can cause stress themselves. Biologists at the Russian Academy of Sciences measured the levels of cortisol in the hair of 20 women who suffered from severe depression and 20 women who did not show symptoms of depression. The women who suffered from depression showed far lower levels of cortisol than women who did not.

“Cortisol stimulates the recovery processes after stress. When a large excess of cortisol accumulates, it means the body had excessive stress load. But if the accumulated amount is substantially less than it should be, it means this important system is exhausted, and the ‘repair mechanism’ after stress doesn’t work at its ful,” said Natalia Gulyaeva, deputy director and head of the Laboratory of Functional Biochemistry of the Nervous System in the Institute of Higher Nervous Activity and Neurophysiology and the leader of the research, told Sputnik News. “Thus, the effect of particular stress on the health is even stronger.”

The researchers noted that this method of measuring cortisol levels will be key to understanding how to treat and prevent depression.

“Our approach allows knowing for certain that the patient’s reaction to stress is inadequate and that it’s harder for him to cope with everyday stress than a healthy person,” said Gulyaeva.

A single centimeter of hair can reflect a person’s cortisol levels for the past month, and cortisol can be used to determine other factors and illnesses aside from stress and depression. Cortisol levels are associated with heart disease, chronic disease and chronic pain. Measuring cortisol amounts can also be used to determine exposure to drugs and environmental toxins, according to a 2007 study published by the National Institutes of Health.