New bipolar disorder treatments tested

New bipolar disorder treatments tested

September 2, 2007 11:15:46 AM PST

Associated Press

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."

___

On the Net:

Bipolar information: http://www.nimh.nih.gov/healthinformation/bipolarmenu.cfm

National Alliance on Mental Illness: http://www.nami.org

Depression and Bipolar Support Alliance: http://www.ndmda.org

Disease treatment studies: http://www.clinicaltrials.gov

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