In the past, researchers have looked at the relationship between cortisol levels and mental health. However, few of them have looked at the stress hormone as an indicator of depression. In a recent study by a group from The Ohio State University, researchers observed the potential relationships of the concentration of the stress hormone cortisol in the hair and depression symptoms of adolescents.
In a publication in July's issue of Psychoneuroendocrinology, lead researcher Jodi Ford and his team report that high levels of cortisol correspond to a higher chance of depression. The relationship between cortisol levels and depression, however, is not linear as they found. Ford stated that cortisol levels that are either too low or too high are not good for the brain, which means that there is a middle level that may be considered normal. The reason for this is yet to be found, but it may possibly be attributed to the decrease in stress response in some people, which results in a decrease in cortisol production or a change in how it is processed.
In the study of 432 adolescents aged 11 to 17, it was also found that adolescents who felt supported at home showed lower levels of depressive symptoms. The teens were asked to answer a questionnaire with nine questions, rating their experience in some areas such as the frequency of how they feel that life is a failure or how often have they felt that people are not friendly to them. The researchers then took a three-centimeter long hair sample, which they assessed would be enough to determine the cortisol levels for the past three months. They have then found that both low and high cortisol levels had a relevant relationship to depression. From this study, one in eight teens has been through a major depressive episode. They also found that the proportion of adolescents battling with depression has increased in the last ten years.
The researchers emphasize that an indicator such as this would be very helpful in the clinical setting. Not to mention, it is also a relatively cheap test. Ford said that the research has opened a number of future research questions, and will not be used until the relationship is better understood.
