Enter e-mail address to receive
popsci weekly updates to your inbox.
Last fall the FDA ruled that all
antidepressants must carry the strongest possible safety
warning after a review of tests revealed that the drugs
trigger suicidal thoughts in 2 to 3 percent of kids and
teens taking them.
Paradox Why antidepressants may exacerbate
depression and anxiety in some kids and
An estimated 20 million Americans
have at one point or another relied on Prozac or one of its
chemical siblings, including Paxil and Zoloft, to ease
depression or anxiety. For most adults who take them, the
drugs, known collectively as selective serotonin reuptake
inhibitors, or SSRIs, work as advertised: Mood improves with
increased levels of the brain chemical serotonin.
a growing body of research is confirming long-standing
suspicions that SSRIs harbor a dark side. Instead of easing
depression, in some patients they may intensify it and even
induce suicidal or violent behavior. This past October,
Columbia University researchers stoked the debate with a study
suggesting that exposure to Prozac in the womb and in early
childhood may permanently alter the brain’s circuitry and
disrupt neural development, leading to serious emotional
disorders later in life. Scientists say that the results,
published in the journal Science, raise serious concerns about
the long-term safety of SSRIs in the estimated 1.75 million
children now taking them.
In the experiment,
researchers gave Prozac to a group of young mice during a
period of brain development that corresponds with the last
trimester of pregnancy through eight years of age in humans.
Then they conducted a series of tests designed to measure
confidence and ability to cope with stress. Compared with
normal mice, adult mice given Prozac early in life were less
willing to take risks to earn rewards, took longer to escape
unpleasant sensations, and were more fearful of new
surroundings—all behaviors associated with anxiety and
depression in animals.
The underlying mechanism for
this paradoxical effect is still unknown, but the
investigators suspect that Prozac may impede the flow of
naturally occurring serotonin in the brain. In healthy adults,
serotonin acts as a chemical messenger that regulates mood by
expediting the transmission of nerve impulses from one brain
cell to another. In infants and young children, though, the
chemical also spurs the maturation of brain systems in the
cerebral cortex and limbic system that govern emotional
Of course, it’s a big leap from mice to
people. But other research indicates that SSRIs may have the
same influence on humans. A study conducted last February at
the Carolinas Medical Center in Charlotte compared 17 babies
born to mothers who took SSRIs throughout their pregnancy with
17 babies whose mothers didn’t. The newborns exposed to the
antidepressants were more likely to have tremors, became
agitated more easily, and exhibited unusual sleep patterns—all
symptoms of a stressed nervous system.
intriguing, these results are by no means definitive, and
experts point out that not treating expectant mothers and kids
who suffer from depression can have serious consequences.
Babies are more likely to be premature, and mothers may be
unable to care for them. Yet as Emory University psychologist
and SSRI expert Paul Plotsky points out, there is a distinct
possibility that “we may be changing the brain in subtle ways
that we still don’t understand.”