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 Usher syndrome: Gene therapy restores hearing and balance
25.09.2017 | Institut Pasteur

nachricht MRI contrast agent locates and distinguishes aggressive from slow-growing breast cancer
25.09.2017 | Case Western Reserve University

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: The fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Bacterial Nanosized Speargun Works Like a Power Drill

26.09.2017 | Life Sciences

The fastest light-driven current source

26.09.2017 | Physics and Astronomy

Beer can lift your spirits

26.09.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>