Trazodone is used to treat depression. It is thought to work by increasing the activity of serotonin in the brain. Trazodone is an antidepressant. This medicine is available only with your doctor's prescription. This product is available in the following dosage forms: Trazodone is used to treat major depressive disorder. It may help to improve your mood, appetite, and energy level as well as decrease anxiety and insomnia related to depression. Overview: Trazodone is used to treat depression. It works by increasing the amount of serotonin, a natural chemical in the brain. Common side effects may include swelling, blurred vision. Why is this medication prescribed? Trazodone is used to treat depression. Trazodone is in a class of medications called serotonin modulators. It works by increasing the amount of serotonin, a natural substance in the brain that helps maintain mental balance. Trazodone is an antidepressant that is sometimes prescribed as a sleep aid. It is not addictive and may offer additional benefits over other sleep aids for certain conditions, such as sleep apnea. Data from open and double-blind trials suggest that the antidepressant efficacy of trazodone is comparable to that of amitriptyline, doxepin, and mianserin. Furthermore, trazodone has shown anxiolytic properties, low cardiotoxicity, and relatively mild side effects. [28] Learn about the side effects of trazodone, from common to rare, for consumers and healthcare professionals.