Research Is Again Looking at Tamoxifen

In 2000, I reported on the serendipitous discovery of Tamoxifen as a treatment for mania which had arisen out of breast cancer research. (See Tamoxifen - Serendipity for Bipolar Disorder?). In September 2007, a research team released findings regarding a chemical called protein kinase C, which is found in the nervous system and seems to be implicated in the symptoms of mania (Bipolar Disorders: An International Journal of Psychiatry and Neurosciences).

It is believed that protein kinase C regulates the function of neurons and neurotransmitters. Tamoxifen inhibits – prevents the work – of this protein, which the research team believes can quickly reduce the symptoms of mania. Their findings report that “the antimanic effects of tamoxifen were rapid, showing significant improvement as early as day 5” compared to the average 14 days it takes for lithium and many of the anticonvulsants to show improvement in manic symptoms.

A new study was released in March that supports the findings of earlier studies. This study improved the design and statistical power of earlier studies, but still reported fantastic numbers. After three weeks of treatment, 48 percent of those taking Tamoxifen showed a 50 percent reduction in symptoms compared to only 5 percent of those given placebo. This is a promising new direction for the treatment of mania; however, further research and development is needed before Tamoxifen, or other selective PKC inhibitors, can be approved as a viable treatment for bipolar disorder. ~ Kimberly