New Bipolar Disorder
Treatments Tested
(September 2, 2007) -- New York - Scientists are testing seasickness
patches and other surprising options in a challenging search for new ways to
treat the
crushing depression and
uncontrolled mania of
bipolar disorder.
Also called manic-depression, it's an illness that can rip careers and
marriages apart and drive people to
suicide. And it's so complex and
mysterious that researchers haven't developed a medication specifically for
it since
lithium, more than half a century ago.
Yet bipolar appears in various forms and severity in about 1 in every 25
American adults at some point in their lives, according to a major study
published in May.
Current medicines help, but often fall short.
They "certainly reduce symptoms but don't do a good enough job," said Dr.
Husseini Manji of the National Institute of Mental Health. "Many patients
are helped, but they're not well."
Nobody knows yet whether the latest crop of possible treatments will pan
out. Besides the motion sickness patch, unusual choices include a drug that
treats Lou Gehrig's disease and a device that produces an electric field
around the brain. Even the breast cancer drug tamoxifen has been tested.
Some of these approaches were identified by logic, and others by pure
chance. Scientists already have early evidence that someday they may prove
useful against bipolar.
The disorder's classic feature is episodes of mania, which are periods of
boosted energy and restlessness that can run for a week or more.
"You have so much energy, you have so many great ideas" said Tamara, 26,
a Pittsburgh resident who was diagnosed several years ago. She asked that
her last name not be used.
"You feel like you're thinking so clear, you've got the answer for
everybody. You need to tell them, you need to phone all your friends... It's
so hard to sleep. You keep thinking of all sorts of things."
But mania can also bring extreme irritability. Tamara's energetic
charisma made her the life of the party, but "if somebody spilled a drink on
me, I would just explode," she recalled. "It's like all your emotions are
just completely intensified."
She got into fights and experienced road rage. She made bad decisions,
plagiarizing a college paper and behaving promiscuously.
"A lot of things sound like a good idea when you're manic," she said, "and
they're really not."
During manic episodes many people even get hallucinations or delusions,
and Tamara experienced those too. "I was convinced I could hear other
people's thoughts, or at least know what they were," she recalled. "I
thought everybody was saying bad things about me."
The other side of the bipolar coin is episodes of depression that last a
week or more. For Tamara, depression was life turning gray.
"Nothing is interesting. You're bored with everything... Nothing sounds
fun anymore. All you want to do is sleep. I slept days and days away."
In her senior year of college, thoughts of suicide frightened her into
seeking help.
Doctors currently
treat bipolar with a variety of drugs including lithium,
anticonvulsant medications that can
stabilize mood, and antipsychotics.
Psychological therapy and patient education greatly boost the effectiveness
of the drugs.
Tamara takes lithium and another drug, and says, "I'm doing fine right
now."
She's lucky. Bipolar disorder is hard to treat chiefly because the
depressive episodes are more severe and more resistant to therapy than
ordinary "unipolar" depression, notes Dr. Andrea Fagiolini, an associate
professor of psychiatry at the University of Pittsburgh.
What's more, many patients can't tolerate current bipolar medications
because of side effects like weight gain, sleepiness, tremor, and the sense
of feeling "drugged," Fagiolini said. (Some patients also stop taking their
medicine because they miss the "highs" of the disease, he noted).
A study of treated patients published last year found that about 60
percent got well for at least eight weeks, but only half of that group
remained well when followed for up to two years. And this was with very good
therapy, noted Dr. Andrew Nierenberg, professor of psychiatry at Harvard
Medical School.
"That means there's a lot of room for improvement," Nierenberg said. "That's
why we need new treatments."
But there's a basic problem. Just as heart attacks come from chronic
heart disease, the manic and depressive episodes come from an underlying
chronic brain disease. And "we just don't really understand what's behind
the illness," said Dr. Gary Sachs, who directs bipolar research at Harvard's
Massachusetts General Hospital.
That mystery and the complexity of the disorder have discouraged
scientists from trying to develop drugs for bipolar, Manji said. Not since
lithium, developed more than 50 years ago, have they developed a drug
specifically for bipolar, Manji said.
Like lithium, some of the latest crop of early candidate drugs revealed
their potential simply by chance.
Take the experience of NIMH researchers Maura Furey and Dr. Wayne Drevets
with the drug scopolamine, which is normally used to keep people from
getting seasick or carsick. Several years ago, they were studying whether
scopolamine could improve memory and attention in depressed people. So they
gave the drug intravenously to depressed patients, trying to find the right
dose for a brain-imaging study.
But then they noticed an odd thing. These patients started feeling less
depressed the night after the injections, a remarkable thing since most
antidepressants take weeks to kick in.
"Some patients would say it was the best night of sleep they'd had in
many years, and the next morning they woke up feeling a substantial lifting
of their depression," Drevets said. "In many cases that improvement
persisted for weeks or even months."
Drevets and Furey quickly changed their research focus to test the drug's
effect on depression itself. And in October 2006 they published an
encouraging, though preliminary, result with a small group of depressed
patients, some of whom had bipolar.
Now Furey is leading a study using scopolamine skin patches — like those
travelers wear to prevent motion sickness — to treat depression in bipolar
disorder as well as ordinary depression. For now, people shouldn't try patch
treatment for depression on their own, she said.
A similar bit of serendipity showed up at McLean Hospital in Belmont,
Mass., in 2001. Depressed bipolar patients who were getting their brains
scanned for a study of brain chemistry suddenly felt a lot better. Alerted
by a research assistant, scientists started taking a closer look. And in
2004, they published their conclusion that the electric fields produced by
the brain scans might lift depression. It's still not clear how.
Follow-up studies have had inconsistent results. But researchers have now
built a device that resembles a hair-salon dryer to produce electric fields.
They plan to start testing it this fall.
Apart from luck, researchers have taken advantage of the few insights
they have into bipolar disease to develop potential treatments.
That's the story with riluzole, now used to treat the paralyzing disorder
Lou Gehrig's disease, also known as ALS or amyotrophic lateral sclerosis.
Scientists found that a drug that's effective against depression in bipolar
disorder boosts the abundance of a certain protein in rat brain cells, and
that riluzole does too. So the researchers tried riluzole in a small number
of depressed bipolar patients, and in some patients the symptoms virtually
disappeared, Manji said.
So riluzole, which is distributed by Sanofi-Aventis, might become a
treatment for bipolar disorder, he said.
Similar research used an off-the-shelf drug to get a lead for developing
a new medication. Studies in rats showed that lithium and another anti-mania
drug hamper the effect of a particular enzyme in the brain. That suggested
that other drugs that hamper that enzyme might work against mania too, Manji
said.
The best available candidate: tamoxifen, used to fight breast cancer. And
sure enough, Manji's recent study in a small group of bipolar patients found
that tamoxifen quickly quelled mania. Other studies have found similar
results, he said.
That shows the value of blocking the enzyme, and now Manji is trying to
develop other drugs that will do that, perhaps for use in emergency rooms.
He wants to avoid tamoxifen itself because of concern about long-term side
effects, since his work requires a higher dose than women use to stave off
breast cancer for years.
Scientists say the real key to unlocking the mysteries of bipolar
disorder — and thereby exposing targets for drugs — lies in a new generation
of research into DNA.
In recent months, scientific journals have begun to publish the early
results of a revolution in DNA analysis: the ability to scan entire genomes
in detail to find genetic variants that predispose people to particular
diseases. Some of the new work is implicating dozens of variants in bipolar
disorder.
Such work can expose the hidden biological underpinnings of disease, and
so tip off researchers to unsuspected targets for intervening.
"We've been stumbling in the dark for most of our history" of bipolar
research, said gene expert Dr. Francis McMahon of NIMH. But "these kinds of
studies ... will really give us the chance to reason from biological
insights back to the patient."
Sachs, of Harvard, agreed: "I think these whole-genome scans will in fact be
the important bridge to better treatments."
And not just in some far-distant future. The new gene studies, Sachs said,
help give "a great potential to advance the field in our lifetimes and treat
people who are living now."
By Malcolm Ritter, AP Science Writer
Source: Associated Press
Last updated: 09/07
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