Antidepressant

Antidepressant medications are "mood-stimulating drugs used primarily in the treatment of affective disorders and related conditions. Several monoamine oxidase inhibitors are useful as antidepressants apparently as a long-term consequence of their modulation of catecholamine levels. The tricyclic compounds useful as antidepressive agents (tricyclic antidepressant) also appear to act through brain catecholamine systems. A third group (second-generation antidepressant agents) is a diverse group of drugs including some that act specifically on serotonergic systems."

Classification

Second-generation antidepressants

Second-generation antidepressants are a "structurally and mechanistically diverse group of drugs that are not tricyclics or monoamine oxidase inhibitors. The most clinically important appear to act selectively on serotonergic systems, especially by inhibiting serotonin reuptake."

Tricyclic antidepressants

Tricyclic antidepressants are "substances that contain a fused three-ring moiety and are used in the treatment of depression. These drugs block the uptake of norepinephrine and serotonin into axon terminals and may block some subtypes of serotonin, adrenergic, and histamine receptors. However the mechanism of their antidepressant effects is not clear because the therapeutic effects usually take weeks to develop and may reflect compensatory changes in the central nervous system."

Monoamine oxidase inhibitors

Monoamine oxidase inhibitors are a "chemically heterogeneous group of drugs that have in common the ability to block oxidative deamination of naturally occurring monoamines".