November 10, 2011
Science Daily/Umeå University
People with recurrent depressions or those exposed to chronic stress exhibits shorter telomeres in white blood cells.
The telomere is the outermost part of the chromosome. With increasing age, telomeres shorten, and studies have shown that oxidative stress and inflammation accelerates this shortening. On this basis it has been suggested that telomere length is a measure of biological aging, and telomere length has subsequently been linked to age-related diseases, unhealthy lifestyle, and longevity.
The research team shows that shorter telomere length is associated with both recurrent depression and cortisol levels indicative of exposure to chronic stress.
"The test revealed that cortisol levels indicative of chronic stress stress are associated with shorter telomeres in both depressed and healthy individuals," says Mikael Wikgren, a doctoral candidate in the research group.
The fact that depressed patients as a group have shorter telomere lengths compared to healthy individuals can be largely explained by the fact that more depressed people than healthy people have disturbed cortisol regulation, which underscores that cortisol regulation and stress play a major role in depressive disorders.