Close to 6 million individuals in the U.S. have bipolar disorder. This disorder, characterized by severe mood shifts ranging from extreme mania to depression can create havoc in one’s life.

Manic episodes may last anywhere from 7 days to several months and the symptoms may range from acute restlessness, trouble sleeping, anxiety, irritability, distractibility and/or paranoia. While the depressive episodes are treatable, the manic phases of bipolar disorders are very difficult to treat. The few drug treatments available to date have to be taken for many weeks and often fail to work or worsen the depression. Even when the treatment works, many individuals rapidly develop resistance to the drugs. During the manic phase of the disorder, individuals may lose their jobs, spend a lot of money, and have poor martial relationships.

For some years now, scientists have been trying to discover treatments that work faster and resolve the bipolar phase without causing excess depression.

Tamoxifen is a widely used drug to treat postmenopausal women who have had breast cancer. It acts by blocking activity of the hormone estrogen, which stimulates breast cancer growth. Tamoxifen also inhibits a group of enzymes known as protein kinase C, and it was this activity that first fascinated scientists studying bipolar disorder.

Now, there is evidence that perhaps tamoxifen may be useful in the treatment of manic phase of bipolar disorder.