Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Manic phase of bipolar disorder benefits from breast cancer medication

13.09.2007
Tamoxifen treats mania faster than some standard medications

The medication tamoxifen, best known as a treatment for breast cancer, dramatically reduces symptoms of the manic phase of bipolar disorder more quickly than many standard medications for the mental illness, a new study shows. Researchers at the National Institutes of Health’s National Institute of Mental Health (NIMH) who conducted the study also explained how: Tamoxifen blocks an enzyme called protein kinase C (PKC) that regulates activities in brain cells. The enzyme is thought to be over-active during the manic phase of bipolar disorder.

By pointing to PKC as a target for new medications, the study raises the possibility of developing faster-acting treatments for the manic phase of the illness. Current medications for the manic phase generally take more than a week to begin working, and not everyone responds to them. Tamoxifen itself might not become a treatment of choice, though, because it also blocks estrogen – the property that makes it useful as a treatment for breast cancer – and because it may cause endometrial cancer if taken over long periods of time. Currently, tamoxifen is approved by the Food and Drug Administration for treatment of some kinds of cancer and infertility, for example. It was used experimentally in this study because it both blocks PKC and is able to enter the brain.

Results of the study were published online in the September issue of Bipolar Disorders by Husseini K. Manji, MD, Carlos A. Zarate Jr., MD, and colleagues.

Almost 6 million American adults have bipolar disorder, whose symptoms can be disabling. They include profound mood swings, from depression to vastly overblown excitement, energy, and elation, often accompanied by severe irritability. Children also can develop the illness.

During the manic phase of bipolar disorder, patients are in “overdrive” and may throw themselves intensely into harmful behaviors they might not otherwise engage in. They might indulge in risky pleasure-seeking behaviors with potentially serious health consequences, for example, or lavish spending sprees they can’t afford. The symptoms sometimes are severe enough to require hospitalization.

“People think of the depressive phase of this brain disorder as the time of risk, but the manic phase has its own dangers,” said NIMH Director Thomas R. Insel, MD. “Being able to treat the manic phase more quickly would be a great asset to patients, not just for restoring balance in mood, but also because it could help stop harmful behaviors before they start or get out of control.”

The three-week study included eight patients who were given tamoxifen and eight who were given a placebo (a sugar pill); all were adults and all were having a manic episode at the time of the study. Neither the patients nor the researchers knew which of the substances the patients were getting.

By the end of the study, 63 percent of the patients taking tamoxifen had reduced manic symptoms, compared with only 13 percent of those taking a placebo. Patients taking tamoxifen responded by the fifth day – which corresponds with the amount of time needed to build up enough tamoxifen in the brain to dampen PKC activity.

The researchers decided to test tamoxifen’s effects on the manic phase of bipolar disorder because standard medications used to treat this phase, specifically, are known to lower PKC activity – but they do it through a roundabout biochemical route that takes time. Tamoxifen is known instead to block PKC directly. As the researchers suspected would happen, tamoxifen’s direct actions on PKC resulted in much faster relief of manic symptoms, compared with some of the standard medications available today.

“We now have proof of principle. Our results show that targeting PKC directly, rather than through the trickle-down mechanisms of current medications, is a feasible strategy for developing faster-acting medications for mania,” said Manji. “This is a major step toward developing new kinds of medications."

Findings from another recent NIMH study strengthen the results. This previous study showed that the risk of developing bipolar disorder is influenced by a variation in a gene called DGKH. The gene makes a PKC-regulating protein known to be active in the biochemical pathway through which standard medications for bipolar disorder exert their effects – another sign that PKC is a promising direct target at which to aim new medications for the illness.

“Mania isn’t just your average mood swing, where any of us might feel upbeat in response to something that happens. It’s part of a brain disorder whose behavioral manifestations can severely undermine people’s jobs, relationships, and health,” said Zarate. “The sooner we can help patients get back on an even keel, the more we can help them avoid major disruptions to their lives and the lives of people around them.”

Susan Cahill | EurekAlert!
Further information:
http://www.nimh.nih.gov/
http://www.nimh.nih.gov/healthinformation/bipolarmenu.cfm
http://www.nih.gov

More articles from Health and Medicine:

nachricht GLUT5 fluorescent probe fingerprints cancer cells
20.04.2018 | Michigan Technological University

nachricht Scientists re-create brain neurons to study obesity and personalize treatment
20.04.2018 | Cedars-Sinai Medical Center

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>