Antidepressants are medications used to treat depression and several other disorders. With proper treatment, often including antidepressants, 70% - 80% of people with major depressive disorder (MDD) can achieve a significant reduction in symptoms.1.ricyclic antidepressants drugs have been used to treat depression since the 1950s. This type of depression medication acts on neurotransmitters like serotonin and other chemicals as well. Tricyclics include drugs like: 1  Amitriptyline (Elavil, Levate). 2  Amoxapine (Asendin). 3  Clomipramine (Anafranil).