Aptazapine (developmental code name CGS-7525A) is a tetracyclic antidepressant (TeCA) that was assayed in clinical trials for the treatment of depression in the 1980s but was never marketed. It is a potent ñ<sub>2</sub>-adrenergic receptor antagonist with about 10 times the strength of the related compound mianserin and has also been shown to act as a 5-HT<sub>2</sub> receptor antagonist and H<sub>1</sub> receptor inverse agonist, while having no significant effects on the reuptake of serotonin or norepinephrine. Based on its pharmacological profile, aptazapine may be classified as a noradrenergic and specific serotonergic antidepressant (NaSSA).