Medications For Bipolar Disorder's Manic Phase May Be Feasible

Scientists may be able to develop faster-acting medications for the manic phase of bipolar disorder, new research shows.

Current medications take several days to weeks to work, during which the extreme mood shifts of the disease may cause patients to engage in harmful behaviors, such as risky health behaviors or spending sprees. Bipolar disorder, also called manic-depressive illness, affects about 5.7 million Americans age 18 and older in any given year.

The faster medications would be aimed more directly at a molecular site on brain cells that current medications, such as lithium and valproate, reach through a slower, roundabout route. By targeting the site with a protein fragment they designed, NIMH scientists reduced manic-like behaviors and associated brain changes in rats. Jing Du, Ph.D., Husseini Manji, M.D., and colleagues published their results in the January 2 issue of The Journal of Neuroscience.

With further research, the molecular site could become a target for new medications for humans, or could point the way to other targets for new treatments, the scientists say. The site is an amino acid, serine 845 (S845), in the GluR1 subunit of the AMPA receptor. (See "About the Science.").

The researchers also pinpointed a region of the brain that appears to be involved in mania: the CA1 region of the hippocampus, which feeds stored memories to the prefrontal cortex, the "active-thinking" part of the brain.