A recent study in the UK has revealed a eureka moment for health. A biological marker has been found for clinical depression for teenage boys. This achievement is a milestone for a health researchers who have made slow progress until now in identifying the biological signposts of depression.
The study, funded by the Wellcome Trust, has found that teen boys who have elevated levels of the hormone known as cortisol, in combination with depressive symptoms, are more likely–by a factor of as much as 14 times–to experience clinical depression than boys with neither marker. As approximately one in six people are expected to suffer from clinical depression during his lifespan, this information is timely indeed.
Leading the Cambridge University study, Dr. Ian Goodyer states that depression is a major illness which might affect up to 10 million people in the UK during their lifetimes. He discussed the impact of the study, saying that with a method available for identifying which teenage boys are most likely to develop major depression, specialists will be better able to target interventions and even prevention strategies toward teens with these markers.
The hope is that such interventions, informed by the new biological marker, will reduce the likelihood of these teens developing major depression and its attendant consequences as adults. As three-quarters of mental health diseases will have their inceptions before the age of 24 years, this advance is noteworthy in that these biological markers for depression will be found and boys at higher risk will be offered treatment at an earlier age, a triumph in a long-running health battle.
The study was conducted in London. Cortisol measurements were taken from the saliva of two separate cohorts of teens. The first cohort of 660 students provided four samples in one week, timed for early in their school day. They provided another set of samples 12 months later. Researchers used these samples to show that cortisol levels in this cohort were stable for both boys and girls over the course of that year.
A somewhat larger cohort of 1,198 students provided similar early-morning samples throughout a three day period. These subjects self-reported any current depression symptoms. These symptom reports were collected longitudinally over the next year and were combined with the cortisol findings. Using this method, researchers divided the teens from the first cohort into four sub-groups ranging from subjects with normal cortisol levels and low depressive symptomology to subjects with elevated cortisol levels and high depressive symptomology; Group One and Group Four respectively.
The results confirmed the previous estimates that one in six persons will experience depression; Group Four subjects made up approximately 17 percent, or one in six, of all subjects in the study. The teens in Group Four were further found to be seven times more likely to develop clinical depression than the subjects from Group One, and two to three more times more likely to do so than subjects from the other two groups. As the study found identical results from both cohorts, the findings were both repeatable and could be combined; the final sample size of the study was of 1,858 individuals, a significant grouping.
The study, published Feb. 17 in the Proceedings of the National Academy of Sciences, was able to support their findings with previously published work. The teens in Group Four were less able to provide specific autobiographical data in their self-reporting of depressive symptoms than those in Group One. Previous studies have shown evidence that high levels of cortisol can act to suppress autobiographical memory recall in subjects.
Put together, these cortisol levels along with the symptoms of depression found in the teen boys constitutes a biological marker. As cortisol levels are generally higher for girls and women than for boys and men, this study did not present the same findings for the girls in the cohort studied.
While the boys in Group Four were up to 14 times more likely to develop clinical depression than the boys in Group One, Group Four’s girls were found to be only four times more likely than those of Group One to develop major depression. Further study is needed to determine a similar markers for depression for teenage girls.
The study is still a landmark in scientific circles. Dr. Matthew Owens, an author of the study from Cambridge University, points out that this new bio-marker may allow specialists to tailor their approaches, personalizing their methods for boys who may carry risk factors for depression. He states that this study may in fact lead to a reduction in the number of people living with clinical depression, a particularly timely factor in an era when suicide rates among teenage boys and young men appears to be increasing. The fact that a biological marker has been found to predict the onset of clinical depression in boys is a first step in the struggle for improved mental health for all.
By Kat Turner