Emsam (selegiline transermal system) is a transdermal patch using the monoamine oxidase inhibitor (MAOI) selegiline. Selegiline, in small doses, is most commonly used in the treatment of Parkinson's disease. It is also effective in higher doses for the treatment of major depressive disorder. On February 28, 2006 the FDA approved EMSAM for the treatment of clinical depression.