Antidepressants are kinds of psychopharmaca, working against depression and anxiety, enhancing motivation. Therapy results are shown retarded after a period of 10 to 14 days.
The oldest representatives of this group are the so-called Tricyclic Antidepressants because of their chemical structure. They affect several neurotransmitters at the same time and show accordingly unwanted adverse effects. Therefore they are today only used in heavy cases, also like the Tetracyclic Antidepressants.
Substantially smaller adverse effects show antidepressants, which affect selectively only one neurotransmitter. The "Selective Serotonine Reuptake Inhibitors" (SSRI) blocks the reuptake of Serotonine at the synapses, as Fluoxetine for example. Accordingly also Norepinephrine Reuptake Inhibitors (NARI) and combined Serotonine-Norepinephrine Reuptake Inhibitors (SNRI) exists.
Mild forms of depressions can be treated with St. John's wort (Hypericum perforatum) which improves mood.
Alternativly, MAO-inhibitors like Tranylcypromine are used as antidepressent.