High levels of cortisol could predict the risk of clinical depression in teenage boys, researchers from the University of Cambridge have suggested.
The researchers found that those with raised levels of the stress hormone, cortisol, and symptoms of depression were up to 14 times more likely to develop clinical depression.
This is the first time that a 'biological signpost' has been found in identifying clinical depression, due to the varied causes and symptoms of the illness.
The researchers hope that this will allow primary healthcare professionals to identify boys at high risk and consider new mental health strategies for this section of the population.
Professor Ian Goodyer from the University's Department of Psychiatry, who led the study, said: 'Through our research, we now have a very real way of identifying those teenage boys most likely to develop clinical depression. This will help us strategically target preventions and interventions at these individuals and hopefully help reduce their risk of serious episodes of depression and their consequences in adult life.'
The researchers collected saliva samples from two separate cohorts of male and female teenagers, the first consisted of 600 participants, the second consisted of 1198 participants. They also took self-reported information on symptoms of depression. The researchers used this information to divide the teenagers into one of four groups depending on their cortisol levels and symptoms of depression. After following the groups for 12 to 36 months, the researchers were able to work out which group was most likely to develop depression and other psychiatric disorders.
Boys with high levels of cortisol and depressive symptoms were 14 times more likely to develop clinical depression than those with neither. However, in girls the difference was not as marked. Girls with high cortisol and depressive symptoms were four times more likely to develop clinical depression than those with neither, suggesting that their might be genetic differences in how depression develops.
The study was published in Proceedings of the National Academy of Sciences and can be found at: http://www.pnas.org/content/early/2014/02/13/1318786111