More threads by ladylore


Account Closed
24 September 2007

Serotonin transporter gene allele linked to depression in chronic illness

MedWire News: Patients with chronic illness who carry the short allele for the promoter region of the serotonin transporter gene (5-HTTLPR) are more likely than other chronic disease sufferers to experience depression, perceived stress, and high norepinephrine secretion, which may be linked to worse cardiovascular outcomes, conclude researchers.

It has been demonstrated that the short allele of a functional polymorphism in the 5-HTTLPR interacts with stressful life events to predict depression in healthy individuals. Whether this short allele increases the risk of depression as a result of the stress of chronic illness is not known, explain Christian Otte, from University Medical Center Hamburg-Eppendorf in Germany, and colleagues.

Studying 557 outpatients with chronic coronary disease, the team performed genotyping of 5-HTTLPR, correlating that with current depression, perceived stress, and 24-hour urinary norepinephrine, using the Computerized Diagnostic Interview Schedule and the Perceived Stress Scale, respectively.

The results, published in the American Journal of Psychiatry, show that 17% of the patients were homozygous for the short allele while 52% were heterozygous, and 31% were homozygous for the long allele. Of those carrying a short allele, 25% had current depression, compared with 17% of long homozygotes.

This gave an unadjusted odds ratio of 1.6, and also an adjusted odds ratio of 1.6, after taking into account age and gender. Patients with a short allele also had higher average scores for perceived stress than long homozygotes, at 5.4% versus 4.7%, and higher rates of moderate or high perceived stress, at an odds ratio of 1.6.

It was also revealed that the average 24-hour norepinephrine excretion was higher in short allele carriers than in long homozygotes, at 55.6 ?g/day versus 50.2 ?g/day. Short allele carriers were also more likely to have norepinephrine values in the top quartile, at an odds ratio of 1.7.

"In summary, we found 5-HTTLPR to be modestly associated with depression, greater perceived stress, and higher 24-hour norepinephrine secretion in patients with coronary disease," the researchers say. "Individuals carrying a short allele may be at greater risk of depression in the presence of chronic illness."
Replying is not possible. This forum is only available as an archive.