A physical perspective on lithium therapy

Lithium salts have strong medical properties in neurological disorders such as bipolar disorder and primary headaches, and has recently gathered attention due to its preventive effect on viral attacks. Though the therapeutic effect of lithium was documented by Cade already in the late 1940s, the underlying mechanism of action is still disputed. Acute lithium exposure has an activating effect on excitable organic tissue and organisms, and is highly toxic. The therapeutic effect is achieved through long-term exposure to lower doses, where it, opposite to acute doses, alleviates excessive cellular activity, and induces a strong metabolic response in the organism, with large changes in phospholipid and cholesterol expression. This review investigates how lithium ions affect membrane composition and function, and how lithium response might in fact be the body's attempt to counteract the physical presence of lithium ions at cell level. The presence of lithium ions strongly affects lipid conformation and membrane phase unlike other alkali ions, with consequences for membrane permeability, buffer property and excitability, and ideas for further research in microbiology and drug development are discussed.