New Depression Studies Reveal Persistent Serotonin System Abnormality In Patients

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New Depression Studies Reveal Persistent Serotonin System Abnormality In

Patients

CHAPEL HILL ­ About 10 years ago, Dr. Golden and University of North

Carolina at Chapel Hill colleagues discovered an important new clue to the

cause of depression, one that other researchers eventually confirmed.

They found that depressed people showed a blunted hormonal response to a

test he developed that boosts serotonin, an important neurotransmitter

chemical in the brain.

" This neuroendocrine challenge test, which involved giving depressed

volunteer patients a medicine called clomipramine, indicated that depressed

patients¹ serotonin systems were sluggish in response and not working

efficiently, " Golden said. " An analogy I use is that their serotonin

Œengine¹ needs a tune-up because they aren¹t getting much mileage out of the

gas being burned. "

Now, newly published work by his laboratory shows that as a group, people

suffering from the illness have that biological abnormality even when they

are not depressed.

" We believe this work is an important step forward in our understanding of

depression because it demonstrates an ongoing trait that distinguishes

patients who have had the illness from the rest of the population, " he said.

" It is strong evidence that depression reflects a genetic trait, which

clinicians have believed for a long time because depression tends to run in

families. "

Golden is professor and chair of psychiatry at the UNC School of Medicine.

In February next year, he will receive the American College of

Psychiatrists¹ annual award for contributions to mood disorders research.

A report on the findings appears in the May issue of

Neuropsychopharmacology, a scientific journal. Besides Golden, authors

include biostatistician R. Ekstrom, Drs. ph M. Bebchuk and Martha

E. Leatherman, both former postdoctoral fellows, and Dr. C. Garbutt,

professor of psychiatry.

One of the body¹s most important neurotransmitters, serotonin helps regulate

many emotional and physiologic functions that are disturbed when people

suffer from depression, Golden said.

With the help of 20 affected patients -- plus non-depressed " control "

subjects -- the UNC team measured changes in levels of prolactin and several

other hormones released by the pituitary gland at the base of the brain in

response to the serotonin challenge test. Their goal was to learn whether

the abnormality was always present or detectable only when patients were

depressed and disappeared like fevers do when infections end.

They then treated the patients and tested them again at the end of acute

therapy, at the end of a year and a fourth time a month or so after they

completed their treatments.

" To our surprise, in that medication-free state of remission, most of them

still demonstrated a blunted hormonal response to serotonin challenge, "

Golden said. " That means that even when they are well, their serotonin

systems still do not work as efficiently as in people who don¹t have a

history of depression. It may also mean that those patients with this

persistent abnormality need to stay on medication longer. "

Golden and colleagues now are trying to identify specific genetic components

of the serotonin system that may account for their findings. Besides current

patients, they also are studying former victims of depression and

first-degree relatives to learn more about the condition¹s genetic

intricacies.

" Certainly there won¹t be any one single genetic basis for depression, but

instead multiple genetic vulnerabilities that can increase the chances of

depression emerging, " the physician said.

Depression affects about 10 percent of the U.S. population at some point in

life, he said. Upsetting events such as the death of a loved one, loss of a

job or stress can trigger it, or it can occur out of the blue, he said.

Although more common in women than in men, depression can strike anyone from

old people to children and at any time in life.

" This is a dangerous illness because it is linked to suicide as well as to

considerable suffering in relationships at home, at school and at work. "