Depression can make us physically older by
speeding up the ageing process in our cells,
according to a study.
Lab tests showed cells looked biologically older in
people who were severely depressed or who had
been in the past.
These visible differences in a measure of cell ageing
called telomere length couldn't be explained by other
factors, such as whether a person smoked.
The findings, in more than 2,000 people, appear in
Molecular Psychiatry.
Experts already know that people with major
depression are at increased risk of age-related
diseases such as cancer, diabetes, obesity and heart
disease.
This might be partly down to unhealthy lifestyle
behaviours such as alcohol use and physical
inactivity.
But scientists suspect depression takes its own toll
on our cells.
Telomere shortening
To investigate, Josine Verhoeven from the VU
University Medical Centre in the Netherlands, along
with colleagues from the US, recruited 2,407 people
to take part in the study.
More than one third of the volunteers were currently
depressed, a third had experienced major depression
in the past and the rest had never been depressed.
The volunteers were asked to give a blood sample for
the researchers to analyse in the lab for signs of
cellular ageing.
The researchers were looking for changes in
structures deep inside cells called telomeres.
Telomeres cap the end of our chromosomes which
house our DNA. Their job is to stop any unwanted
loss of this vital genetic code. As cells divide, the
telomeres get shorter and shorter. Measuring their
length is a way of assessing cellular ageing.
People who were or had been depressed had much
shorter telomeres than those who had never
experienced depression. This difference was
apparent even after lifestyle differences, such as
heavy drinking and smoking, were taken into
account.
Furthermore, the most severely and chronically
depressed patients had the shortest telomeres.
Dr Verhoeven and colleagues speculate that
shortened telomeres are a consequence of the body's
reaction to the distress depression causes.
"This large-scale study provides convincing evidence
that depression is associated with several years of
biological ageing, especially among those with the
most severe and chronic symptoms," they say.
But it is unclear whether this ageing process is
harmful and if it can be reversed.
UK expert Dr Anna Phillips, of the University of
Birmingham, has researched the effects of stress on
telomere length.
She says telomere length does not consistently
predict other key outcomes such as death risk.
Further, it is likely that only a major depressive
disorder, not experience of or even a lifetime of mild-
to-moderate depressive symptoms, relates to
telomere length, she said. www.oseni9ja..com/2013/11/depression-makes-us-biologically-older.html?m=1 www.bbc.co.uk/news/health-24897247