Used as an antidepressant for the treatment of major depressive disorder and seasonal affective disorder. Also prescribed to support smoking cessation by reducing withdrawal symptoms and cravings for nicotine. Works by affecting neurotransmitters in the brain, particularly norepinephrine and dopamine, to help improve mood and reduce dependence on nicotine. Available in immediate-release, sustained-release, and extended-release formulations for tailored dosing in psychiatric and behavioral therapy.