Diazepam is used to treat various conditions such as anxiety, insomnia, and muscle spasms. It has a calming effect on the brain and nerves, hence, helps in treating anxiety. Diazepam 10 mg works by increasing the effects of gamma-aminobutyric acid (GABA) in the brain. This, in turn, controls the excess activity of the nerve cells in the brain, thus imparting a calming or tranquilizing effect.