Brain on Fire

Susannah Cahalan (Moretz) is a New York Post writer, who works with her boss Richard (Perry) and desk neighbor/co-worker Margo (Slate). She meets a sound producer named Stephen (Mann) and they become friends. Susannah begins to experience strange things (such as being in a trance state, seeing people — who are not actually present — who talk about her, and hypersensitiveness to annoying noises and tactile sensations). Susannah's behavior becomes unusually erratic. Several days of mishaps made by her in the office due to her shifty behavior, including talking to Stephen while under her desk, as well as insulting a Senator, his public relations person and firm, Susannah suffers a seizure and seeks treatment. Read more on Wikipedia.