More than 5% of all Austrians suffer from depression. However, little is known about the biological basis of this disease. In a new study, scientists led by Alexander Karabatsiakis from the Institute of Psychology at the University of Innsbruck have now observed a strong correlation between the severity of depression and the level of the stress hormone cortisol in hair. Measuring hair cortisol levels could be an important approach for personalized medicine and also in suicide prevention, which is very important in severe depression.
The stress hormone cortisol is involved in vital processes in the human body. In the case of psychological stress, but also in the case of psychiatric illnesses, it is increasingly released and stored in the hair, among other places. Studies have already shown that people suffering from depression can have increased cortisol levels in their hair.
The research group led by Alexander Karabatsiakis from the Institute of Psychology at the University of Innsbruck now also compared these data with hair samples from people who died by suicide. Here, strongly increased cortisol levels were detected in comparison to persons with and without depression. This initial observation could provide new impetus in the field of depression research, but also in suicide prevention,since suicidality can be a very serious complication, especially in people with depression. The results of the study were published in the EPMA Journal of Predictive, Preventive and Personalized Medicine.
Biomarker research as an approach to prevention
"Our biomarker research investigates how psychological stress and psychiatric illnesses are linked to physical and psychosomatic complications," says Karabatsiakis. This interdisciplinary research is also being conducted intensively with scientists* from different disciplines at the Innsbruck science location. "One of the current starting points is the determination of hair cortisol, which can be detected over time. Our new observations on this could be very helpful for the prevention of mental illnesses after stressful situations and their long-term consequences, also for physical health."
Health monitoring via a hair sample is a non-invasive and hardly stressful procedure that could also be carried out in ordinations or in other care models. "If, for example, family doctors were able to measure that a hormonal stress potential is emerging in the body, it might be possible to identify a potential suicide risk even in persons with high psychological stress and to intensify the medical focus on the person accordingly, even if patients themselves do not report any complaints. In terms of prevention, this would already be a great gain, because every person counts," says Karabatsiakis.
Cortisol levels rise with severity of depression
The study thus expands the biological perspective on mental illness. "The cortisol level in the hair increases with the subjectively perceived severity of depressive symptoms," Karabatsiakis explains. "Moreover, the longer one feels depressed, the more active our body’s stress response probably is. However, further research and empirical data are needed to assess stress and risk on an individual basis, since we examined a relatively small number of people in this first study," Karabatsiakis says.
After approval by the responsible ethics committee, hair samples from the forensic medicine department of the Hannover Medical School were also used to conduct the study. For ethical reasons, nothing was known about the hair samples of persons with suicide background other than age, sex, body mass index and that a foreign influence could be excluded as cause of death.
"A continuation of similar studies investigating the prevention potential of hair cortisol, as well as increased research on suicidality, suicide prevention, and their biological mechanisms, are imperative and more urgent than ever," Karabatsiakis said.
Karabatsiakis, A., de Punder, K., Salinas-Manrique, J. et al. Hair cortisol level might be indicative for a 3PM approach toward suicide risk assessment in depression: comparative analysis of mentally stable and depressed individuals versus individuals after completing suicide. EPMA Journal 13 , 383’395 (2022). https://doi.org/10.1007/s13167’022 -00296-z