Neurobiologists from the Institute of Higher Nervous Activity and Neurophysiology of the Russian Academy of Sciences have developed a non-invasive method for analyzing the level of cortisol in the body. A new method for determining the stress hormone in hair will help in the treatment and prevention of depression. Scientists have submitted their work in the journal Metabolic Brain Disease . The research was supported by a grant from the Russian Science Foundation.
Chronic stress is responsible for a variety of mental disorders, including depressive disorders. The pace of modern life creates additional stress factors that accompany urbanization, the continuous increase in the volume of current information, and the complication of social and personal life. The accumulation of negative emotions leads to the fact that the prevalence of depression is steadily increasing, and, according to the forecast of the World Health Organization, by 2030 depression will move to the first place among diseases.
The body’s stress reactivity, that is, its response to stressful stimuli, largely determines the likelihood of developing depression. Therefore, the assessment of stress reactivity allows us to assess the propensity of a person to develop post-stress depression.
“In accordance with our working hypothesis, the pathogenesis of depressive disorders is closely related to the patient’s inability to adequately respond to stress. In other words, impaired stress reactivity is a central biological component of this group of diseases, and its study allows not only understanding the patterns of depression development, but also assessing the patient’s condition and the effectiveness of his treatment, ”says Natalia Gulyaeva, head of the RSF grant.
The stress response is formed by the so-called hypothalamus-pituitary-adrenal axis. The hypothalamus produces a neurohormone , corticotropin- releasing factor (CRF), which stimulates the formation of the hormone adrenocorticotropin (ACTH) in the pituitary gland . This hormone enters the bloodstream and causes the adrenal cortex to secrete stress hormones corticosteroids, mainly cortisol. Cortisol, which travels through the blood to all cells in the body, alters its metabolism, providing the substances that are necessary to adequately respond to stress.
Correction of impaired stress reactivity is a promising approach for effective treatment and prevention of depression. The main molecular and cellular mechanisms underlying stress reactivity and its disturbances are the functioning of the hypothalamic-pituitary-adrenal neuroendocrine axis, and in the brain – the balance of neurotransmitters and neurotrophic factors, as well as the cytokine system. Disruption of these interconnected systems, leading to numerous structural and functional changes in the brain, underlies the pathogenesis of depression. It is these systems and processes that are potential targets for the prevention and treatment of depressive disorders.
However, the validity of a single determination of cortisol in human biological fluids, primarily in blood, is not high due to significant fluctuations in the level of this hormone during the day. Now biologists have developed and tested in practice a new method of non-invasive (without penetration into the body) assessment of the level of cortisol in the human body.
“Determination of cortisol in the hair of depressed patients and healthy people allowed us to compare the functioning of their main stress-implementing link during the month before the examination. Hair cortisol levels were significantly lower in women with depressive disorder than in healthy women of the corresponding age, with hair cortisol levels being lower as the severity of depression increased. This indicates suppression of the hypothalamic-pituitary-adrenal axis in female patients with depression, which is the basis of their impaired stress reactivity, ”Gulyaeva said.
Currently, on the basis of the SPC of Psychoneurology named after Z.P. Soloviev of the Moscow Healthcare Department, which took an active part in the project, clinical trials are continuing using the developed method. This approach provides scientists and clinicians with an effective, non-invasive means of assessing disease progression and the effectiveness of treatment for depression.