Mirtazapine is a prescription antidepressant introduced by Organon in 1996, and marketed under the tradename Remeron® (also: Zispin®, Avanza®, Norset®, Remergil®). It is used primarily for the treatment of clinical depression in adults. It has a tetracyclic chemical structure and is a white to creamy white crystalline powder, distributed in tablets of 15mg, 30mg, and 45mg.