How effective are antidepressants? That's a question that many people with
depression have asked -- and research suggests that the answers aren't simple.
It's a question that's relevant to millions. About one in 10 Americans takes
an antidepressant, now the most commonly prescribed type of drug in the U.S.,
according to research published in 2009 in the Archives of General
Psychiatry. Much of the surge has happened in the past two decades. From
1996 to 2005, the rate of antidepressant use...
"This is true across all countries, all cultures, all
income levels, across all levels of success -- women have higher rates of
depression," says Myrna M. Weissman, PhD, an epidemiologist and psychiatry
professor at Columbia University School of Medicine in New York.
"Before puberty, rates of depression are about equal
between boys and girls," she tells WebMD. "At puberty, the rates
skyrocket in girls. There are men who suffer from depression, but not anything
near the rate in women."
In 1999, Surgeon General David Satcher, MD, noted these same
rates in his report on mental health. Although women have more opportunities
than ever before, they still fight a bigger battle against depression, anxiety,
and other mental health problems.
Under the Skull
Using sophisticated brain imaging, researchers have found that
men's and women's brains are indeed built differently.
In one study, a group of researchers found that men's brains
synthesize more of the mood-lifting brain chemical serotonin than women's
brains do -- 52% more.
Men and women also respond to antidepressant medications
differently. Some antidepressant drugs work better for men while others may
prove to be more beneficial for women.
For women, antidepressant drugs that affect serotonin, like
Prozac, Paxil, and Zoloft, work better, reports Susan G. Kornstein, MD, head of
the outpatient psychiatry clinic at the Virginia Commonwealth University.
Serotonin found primarily in a brain region called the
amygdala, where emotions are processed, explains Stephan Hamann, PhD, a
psychology researcher at Emory University in Atlanta.
This is the "fight-or-flight" center of the brain, the
region that registers anxiety, fear, joy, stress, even lust, he says.
Emotional Secrets of the Amygdala
The amygdala is an almond-shaped area of the brain that
controls emotion. In adulthood, the size of a man's amygdala doesn't differ
much from a woman's. However, recent studies have found that when men and women
look at photographs, they register the memory on opposite sides of the
In studies involving spouses, women could recall memories -
first date, last vacation, a recent argument -- more quickly than men did.
Women's memories were also more emotionally intense and vivid than men's
memories, Hamann adds.
"Women may be more predisposed to experience events more
intensely, more vividly," he tells WebMD. That ability has a downside:
"Women have greater propensity to rumination; going over the same negative
events amplifies its negative consequences."
Animal studies show similar patterns, he says. "The
emotional arousal that leads to stress responses and stress hormones affects
basic memory machinery in male and female rats differently."
Evolution at Work
As our species evolved, this emotional sensitivity helped
females in protecting themselves and their young. On the other hand, "males
want to remember where better hunting grounds are," says Hamann.