A biomarker in cell-free blood plasma can be linked to an overactive stress system in suicidal individuals.

‘The newly measured biological marker indicates greater stress exposure in vulnerable people suffering from various psychiatric conditions such as anxiety and depression.’

The researchers compared 37 patients who had been hospitalised at a
psychiatric clinic after attempting suicide with an equal number of
healthy control subjects. About 70% of both groups were female,
and the average age of the patients was approximately 40.




Compared to the healthy control subjects, the suicidal patients had strikingly increased levels of mitochondrial DNA in their cell-free blood plasma.
The researchers also found that the large amount of mitochondrial DNA in the plasma was linked to higher levels of cortisol in the blood. Cortisol is an important hormone in the body's stress system and high levels of cortisol, which have been found in depressed and suicidal patients in previous studies, are a sign of an overactive stress system.
Previous studies have shown that depressed individuals have an increased level of mitochondrial DNA in their immune cells and that this is linked to stressful life events. Furthermore, studies on animals have shown that increased stress and cortisol levels are linked to higher mitochondrial DNA, but this is the first study to be tested on psychiatric patients.
"We believe the increased levels in suicidal patients are due to their exposure to severe stress for longer periods than the healthy subjects we compared them to. An increased level of cortisol can cause the body's cells to malfunction, which in turn contributes to increased levels of cell-free mitochondrial DNA in the blood", says Lars Ohlsson, senior lecturer at Malmö University.
Advertisement
Source-Eurekalert