Single dose of antidepressant changes brain

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1 Dose of Antidepressant
Changes Brain
Connections?
Researchers eventually hope to
predict who will respond to a drug
and who won't
By Deepak Kumar
THURSDAY, Sept. 18, 2014
Just a single dose of a common antidepressant
can quickly alter the way brain cells communicate
with one another, early research suggests.
The findings, reported online Sept. 18 in Current
Biology , are a step toward better understanding
the brain's response to widely prescribed
antidepressants. Experts said the hope is to
eventually be able to predict which people with
depression are likely to benefit from a drug -- and
which people would fare better with a different
option.
In a small study of healthy volunteers, researchers
found that a single dose of the antidepressant
escitalopram (Lexapro) seemed to temporarily
reduce "connectivity" among clusters of brain
cells in most regions of the brain.
The exceptions were two brain areas -- the
cerebellum and thalamus -- where the drug
boosted connectivity. In simple terms,
connectivity refers to how brain cells "talk" to one
another.
The cerebellum coordinates the body's voluntary
movement, while the thalamus is involved in
movement, sleep, and processing sensory
information, including the things we see, hear and
touch.
It's not clear yet what the findings could mean,
said Dr. Radu Saveanu, a professor of psychiatry
and behavioral sciences at the University of
Miami Miller School of Medicine in Florida.
But Saveanu, who wasn't involved in the study,
said he sees it as an early step toward more
"personalized medicine" for depression. In theory,
brain scans could be used to predict a patient's
likelihood of responding well to a given drug.
"Even though we have a large number of
antidepressants available, we have no good way
of predicting who'll respond to a medication,"
Saveanu said.
However, much research remains before brain
scans could be used to guide anyone's treatment,
he stressed. But the current study is a necessary
first step, Saveanu said, because it looked at how
one antidepressant dose affects depression-free
people's brains.
Now some questions are, how do depressed
people's brains respond? Are they different from
people without depression? And how do people
with depression differ from each other?
The study included 22 healthy adults who
underwent functional MRI scans, which chart
blood flow in the brain, giving an indication of the
brain's electrical activity. Each study participant
underwent three scans on separate days: a
baseline scan; another done three hours after a
dose of Lexapro; and a third done three hours
after a dose of a placebo (inactive) pill.
Lexapro is a selective serotonin reuptake inhibitor
(SSRI), a group of antidepressants that also
includes brands like Paxil, Prozac and Zoloft . The
drugs are widely prescribed, but no one knows
precisely how they act on the brain.
It's been thought that they change the brain's
connectivity, but that those effects probably take
a few weeks to show up, said study researcher
Dr. Deepak Kumar a fellow at the Department Of Pharmaceutical Sciences, M.D.U. Rohtak; India
.