Causes of Depression : Cortisol?

New research from the University of Cambridge may have discovered the first biomarker of clinical depression. This discovery could lead help healthcare providers identify teenage boys who could be at the greatest risk for developing the illness.

Depression is a mental illness that affects one person in six at some point through out their lives. It has been hypothesized that biomarkers are available for the illness, none have ever been found. The believe as to why no previous markers have been found is due to the fact that symptoms of the disorder can vary from person to person.

Researchers looked for an elevation of the stress hormone cortisol in two groups of teenage boys. The first group consisted of 660 boys. Each boy provided four early morning samples of saliva during a typical school week. New samples were obtained within a week, and then a follow up collection occurred a year later.

The second group consisted of 1,198 boys who provided early morning samples over three school days. No follow up samples were given.

Both groups offered used self-reports about their current depression symptoms. These reports were given over a twelve month period and matched to the saliva samples.

“Depression is a terrible illness that will affect as many as ten million people in the UK at some point in their lives,” Professor Ian Goodyer from the University of Cambridge, “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.”

Dr. Matthew Owens, lead author on the study, explains, “This new biomarker suggests that we may be able to offer a more personalized approach to tackling boys at risk for depression. This could be a much needed way of reducing the number of people suffering from depression, and in particular stemming a risk at a time when there has been an increasing rate of suicide amongst teenage boys and young men.”

The information from the two groups were combined and the results were split into four groups. The men from Group 4 were on average seven times more likely to develop clinical depression than those who fell into Group 1. Group four had elevated levels of morning cortisol and high symptoms of depression over time. The group made up approximately one out of every six boys in the group, or roughly 17 percent.

Part of the study required participants to recollect autobiographical memories from example situation. Those who fell into Group 4 were less likely to give a detailed account of a time where the situation occurred. They used more generalized information rather than specific information. This backed up already heavily documented beliefs that high cortisol suppresses memory recall.

The hope is that by having a biomarker that is easily measurable, primary care physicians identify those teenage boys who may be at a higher risk. This will allow them to get the help that they need in order to get better quicker.

Progress in identifying biological markers for depression has been frustratingly slow, but now we finally have a biomarker for clinical depression.” Head of Neuroscience and Mental Health, Dr. John Williams said of the study.