Remeron®, introduced by Organon in 1994, is a noradrenergic and selective serotonergic antidepressant (NaSSA), the first of a new class of therapy. Its active compound, mirtazapine, has a dual-action effect aimed at rectifying the chemical imbalances in the brain that are understood to cause depression.

A deficiency in the brain of two chemicals—norepinephrine and serotonin—is believed to contribute to depressed mood, poor sleep, anxiety, weight loss, and other symptoms of depression. Remeron is understood to act by increasing the release of both these chemicals from nerve cells in the brain, thereby relieving symptoms.

In addition, Remeron blocks two specific serotonergic receptor sites so that they do not become stimulated. Some other types of antidepressant stimulate these sites, which may account for their serotonergic side effects such as insomnia, nervousness, nausea and loss of sexual drive.

Remeron appears to be highly effective and well tolerated by patients. It is available in 30 mg, taken once daily in the evening.