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Rushing
Off
Antidepressants
Can Bring On More Distress At
first, Zoloft seemed like "manna from heaven," says this
53-year-old woman, a teacher who lives in Watertown. It
was the summer of 1999 and, for reasons she still doesn't fully
understand, she had slipped into a "terrible slump." Her
doctor suggested Zoloft, America's second most popular
antidepressant, after Prozac. And for a while, it was great, says
the woman, who does not want her name used. But
after nearly a year on the drug, she developed a twitch in her
left eyelid. It may not have been related to the Zoloft, but since
she was feeling fine, she decided to stop taking the drug. And,
unlike many people who quit antidepressants, she did it the right
way: very slowly - cutting the dose little by little over six
weeks. Even
so, she wound up with three months of withdrawal hell, or
discontinuation syndrome, the term psychiatrists prefer because
withdrawal suggests that antidepressant drugs are addictive (like
cocaine or heroin), which they are not. Discontinuation
syndrome is not a recurrence of the original depression, though
that can happen, too. It's a brand new set of problems, in this
woman's case, bad headaches, vertigo, and dizziness. At one point
during a walk, she says, "my body felt like it was tipping to
one side. I had to keep lying down. It was terrible." Could
a drug that was no longer in her system somehow be causing weird
symptoms she'd never had before? "That
was the thing that got me the most creeped out," she says.
"The drug clearly is out of your body. So what was it
that lasted for three months?" What
lasted so long for this teacher, and many others who stop taking
antidepressant drugs, is what scientists now think of as a
prolonged period of re-adjustment during which the chemistry of
the brain settles into a kind of new, non-depressed normal. To
be sure, many of the millions of people worldwide who take
antidepressants experience no withdrawal symptoms when they stop.
But some studies suggest that one in every 10 have some symptoms
and one in 20 suffer significant distress, says Dr. Jerrold
Rosenbaum, chief of psychiatry at Massachusetts General
Hospital. Others,
among them Dr. Andrew Leuchter, director of the division of adult
psychiatry at the UCLA Medical Center, believe the actual figures
are much higher. Yet
even doctors who should be on the lookout for withdrawal symptoms
- such as dizziness, increased nervousness, irritability,
insomnia, and a dramatic increase in vivid dreams - often aren't
paying close attention. A
1997 study in the Journal of Clinical Psychiatry showed that 70
percent of general practitioners and, surprisingly, a third of
psychiatrists don't know that significant withdrawal symptoms can
occur when people stop taking
antidepressants called selective serotonin reuptake inhibitors, or
SSRIs, including Prozac, Zoloft, Paxil, Luvox, Celexa, and a
similar drug, Effexor. (Withdrawal syndromes can also occur with
antidepressants that work differently from the SSRIs, including
older drugs such as
Elavil and Tofranil) "It's
an under-recognized problem," says Leuchter, because when
people stop taking a drug and then develop new symptoms, they
can't believe it has"anything to do with the medicine
because, if they're not taking it, how can it affect them?" But
withdrawal clearly does happen, though researchers still aren't
sure why. The basic thinking is that depression is caused by a
deficiency of serotonin, a key neurotransmitter in the brain.
SSRIs boost serotonin by stopping its re-absorption into brain
cells, thus keeping more serotonin where it's needed, in the
synapses, or gaps, between nerve cells. As
the brain adapts to increased levels of serotonin, some
neuroscientists think there is a decline in either the number or
sensitivity of the brain's molecular gateways that can put
serotonin to work. Then, when SSRIs are discontinued, withdrawal
symptoms may occur as the nervous system, now primed for lots of
serotonin, isn't getting enough, says Dr. Alexander Bodkin, chief
of clinical psychopharmacology research at McLean Hospital in
Belmont. One
thing researchers are sure of is that the severity of withdrawal
symptoms from SSRIs is closely correlated with how long the drug
remains in the body. The longer the drug or its active metabolic
breakdown products stay in the body, the less severe the
withdrawal. "The
faster-clearing the drug, the worse the withdrawal," says Dr.
Michael Craig Miller, a psychiatrist who edits the Harvard Mental
Health Letter. Prozac
is least likely to cause withdrawal because its metabolic
breakdown products linger in the body for as long as five weeks.
In fact, precisely because of this, one strategy for people who
have trouble getting off other SSRIs is to switch to Prozac and
then taper slowly off of that. By
contrast, Paxil, Luvox, and Celexa may trigger withdrawal because
they are faster-clearing, lingering in the body for just four to
five days. Zoloft lingers slightly longer. Effexor, a variant of
standard SSRIs, has the shortest half-life of all, about 5 hours,
which means it is highly likely to cause withdrawal symptoms. Recent
studies have bolstered the idea that faster-clearing drugs lead to
worse withdrawal. In
1998, Rosenbaum of MGH and his team studied 220 patients and found
that those who abruptly stopped taking Paxil, and to a lesser
extent, Zoloft, had significant withdrawal symptoms, while those
who stopped taking Prozac did not.
Another study published last year in the British Journal of
Psychiatry found essentially
the same pattern. Yet
another study, sponsored by Lilly Research Laboratories (Eli Lilly
makes Prozac) and
published last year in Psychoneuroendocrinology, showed that
people who suddenly
stopped taking Paxil had a significant increase in heart rate and
stress hormone levels, while those taking Zoloft or Prozac did
not. The
bottom line is that if you want to wean yourself from
antidepressants, do so slowly, by decreasing your dose by half
every one to two weeks. It may take weeks or even months to
discontinue completely, but that doesn't really matter. "There's
never a rush in getting off these medications," says Leuchter
of UCLA. "What's the hurry? If you have been on them for six
to 12 months and you're tolerating them well, there's no point in
going too quickly." And
if you do develop withdrawal symptoms despite tapering off slowly,
try going back to the previous dose, then switching to Prozac and
weaning yourself from that. The
most important lesson, says the teacher from Watertown, who is now
symptom-free, is that antidepressants - despite the recent
backlash in the media - significantly help millions of people.
"I would never say, `Don't go on it,' " she says.
"I would just say be very aware that when you want to get off
it, go to a doctor who knows about this." Judy
Foreman is a Lecturer on Medicine at Harvard Medical School. Her
column appears every other week. Past columns are available on www.myhealthsense.com.
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