Lithium: how it might protect the brain

Professor Wayne Drevets discusses ways in which lithium may affect bipolar disorder. It affects multiple neurotransmitter systems and may protect brain structures that are atrophied in bipolar disorder.

The treatments for bipolar disorder were initially discovered serendipitously. Lithium for example remains one of the most frequently used and effective treatments for bipolar disorder, but lithium has a number of different targets in the brain and so we haven’t learned very much specific information from lithium’s effect. Some of the things that lithium does are now targets for a great deal of research. One of those things is that lithium will decrease the function or change the function of some second messenger systems. And so it will give a way that you could have multiple neurotransmitter systems affected or damped-down by just the one effect of lithium. Another thing that lithium does is that it has very robust neuroprotective and neurotrophic effects. It’s thought that lithium may partly have its effect in the brain by restoring the structure, some of these structural abnormalities that occur in bipolar disorder. For example, the reductions in grey matter volume that exist in the hippocampus and the medial prefrontal cortex, there is now some evidence that suggests lithium can actually reverse those changes. Similarly in those experimental animal models I was referring to where you’ve got repeated stress causing atrophy in the same structures, lithium has the capability of reversing those atrophic changes. So, one impact of lithium might be on the neuroplasticity of the brain.