Mianserin, sold under the brand name Tolvon among others, is an atypical antidepressant which is used primarily in the treatment of depression in Europe and elsewhere in the world. It is a tetracyclic antidepressant (TeCA). Mianserin is closely related to mirtazapine, both chemically and in terms of its actions and effects, although there are significant differences between the two drugs. Mianserin, sold under the brand name Tolvon among others, is an atypical antidepressant which is used primarily in the treatment of depression in Europe and elsewhere in the world. It is a tetracyclic antidepressant (TeCA). Mianserin is closely related to mirtazapine, both chemically and in terms of its actions and effects, although there are significant differences between the two drugs. Mianserin at higher doses (30-90mg/day) is used for the treatment of major depressive disorder. It can also be used at lower doses (around 10mg/day) to treat insomnia. It should not be given to be people younger than 18 years old, as it can increase the risk of suicide attempts and suicidal thinking, and it can increase aggressiveness. While there is no evidence that it can harm a fetus from animal models, there is no data showing it safe for pregnant women to take. People with severe liver disease should not take mianserin, and it should be used with caution for people with epilepsy or who are at risk for seizures, as it can lower the threshold for seizures. Very common (incidence>10%) adverse effects include constipation, dry mouth, and drowsiness at the beginning of treatment. Common (1%<incidence≤10%) adverse effects include drowsiness during maintenance therapy, tremor, headache, dizziness, vertigo, and weakness. Uncommon (0.1%<incidence≤1%) adverse effects include weight gain.