Did you know that nearly half of Americans are affected by
some sort of mental disorder at some point in their life? Suicides, 90 percent
of them among the mentally ill, take 40,000 Americans every year and since
2005, the suicide rate among U.S. war veterans has nearly doubled.
At the same time, treatment for
mental disorders can be woefully ineffective. Thirty-three percent of
patients don't respond to any drugs at all. And when they do work, they are
slow - a dangerous risk, given the number of suicides each year.
The treatments don't work well because scientists don't
really understand what they do. Serotonin, the most common target for current
antidepressants, is a neurotransmitter, a chemical that carries messages in the
brain. In early studies of serotonin, researchers thought a lack of serotonin
was the cause for many disorders. Iproniazid was the first of a class of
medicines (called monoamine oxidase inhibitors (MAOIs)) that block an enzyme
from breaking down serotonin as well as dopamine and norepinephrine, two other
neurotransmitters. The chief downside of these drugs is that they require a
strict diet which often causes patients to not take the drug. Deviating from
the diet can cause deadly spikes in blood pressure. Tricyclic antidepressants
work by blocking the re-absorption of serotonin and norepinephrine but they
come with side effects including, dry mouth, weight gain, erectile dysfunction,
and loss of libido.
Research today is starting to find that just adding or
subtracting serotonin in a person doesn't change his or her mood. For example,
Prozac raises serotonin levels within hours yet doesn't change mood for weeks,
and when a healthy person's brain is depleted of serotonin it doesn't make him
or her sad. Serotonin is not just a feel-good chemical. As it falls short of
explaining depression, a most likely candidate is emerging.
The next article will discuss the effect of stress on the
brain and how it relates to depression.
|
Comments rated to be Good Answers:
Comments rated to be "almost" Good Answers: