Brain differences mark those with depression risk Mon Mar 23, 2009
6:53pm EDT
CHICAGO (Reuters) - People who have a high family risk of developing
depression had less brain matter on the right side of their brains on
par with losses seen in Alzheimer's disease, U.S. researchers said on
Monday.

Brain scans showed a 28-percent thinning in the right cortex -- the
outer layer of the brain -- in people who had a family history of
depression compared with people who did not.

"The difference was so great that at first we almost didn't believe it.
But we checked and re-checked all of our data, and we looked for all
possible alternative explanations, and still the difference was there,"
said Dr. Bradley Peterson of Columbia University Medical Center and the
New York State Psychiatric Institute.

His study appears in the Proceedings of the National Academy of
Sciences.

The findings are based on imaging studies of 131 people aged 6 to 54
with and without a family history of depression.

The team was looking specifically for abnormalities in the brain that
could signal a predisposition to depression, rather than changes that
may be caused by the disease.

The thinning on the right side was only linked with a family
predisposition to depression. People who actually were depressed also
had thinning on the left side of cortex.

"Because previous biological studies only focused on a relatively small
number of individuals who already suffered from depression, their
findings were unable to tease out whether those differences represented
the causes of depressive illness, or a consequence," Peterson said.

He said having a thinner right cortex may increase the risk of
depression by disrupting a person's ability to decode and remember
social and emotional cues from other people.

They did memory and attention tests on the study subjects and found the
less brain material a person had in the right cortex, the worse they
performed on attention and memory tests.

"Our findings suggest rather strongly that if you have thinning in the
right hemisphere of the brain, you may be predisposed to depression and
may also have some cognitive and inattention issues," he said.

Peterson said the findings suggest medications used to treat attention
problems such as stimulants might be useful in the treatment of
depression in some patients.

(Editing by Maggie Fox and Xavier Briand)

http://www.reuters.com/article/healthNews/idUSTRE52M7OV20090323?feedType\
=RSS&feedName=healthNews
<http://www.reuters.com/article/healthNews/idUSTRE52M7OV20090323?feedTyp\
e=RSS&feedName=healthNews>



[Non-text portions of this message have been removed]