Antidepressant

An antidepressant is a drug for the treatment of depression. Modern antidepressants are not stimulants and are not generally addictive nor do they produce tolerance. Conversely, stimulants are not usually considered an effective treatment for depression. Antidepressants create little if any immediate change in mood and require between several days and several weeks to take effect. They are believed to act by blocking the reuptake of neurotransmitters such as serotonin in the synapses of neurons.

Note that antidepressants may actually make bipolar disorder worse, and should be used with great care in the treatment of that disorder, usually in conjunction with mood stabilisers. Their use must always be monitored by a psychiatrist. In particular, it has been noted that the most dangerous period for suicide in a patient with depression is after his or her mood begins to improve, when the patient has not fully recovered but has enough energy to take actions that they would have been unable to take before.

Like many psychiatric drugs, antidepressants were discovered by accident, the first antidepressants found in the 1960s and were intended for the treatment of tuberculosis. These drugs were found to have the side effect of improving the patients' mood, which made them unsuitable for their original purpose because the drugs encouraged the patients to be active and not to have the bed rest needed for tuberculosis. However, the newer SSRI antidepressants were the first example of rational drug design.

Many antidepressants also are used for the treatment of anxiety disorders.

Classes of antidepressant:

• selective serotonin reuptake inhibitor (Paxil, Prozac, Luvox, Celexa, Lexapro, Zoloft, etc.)
• tricyclic antidepressant
• tetracyclic antidepressant[?]
• monoamine oxidase inhibitor
• novel antidepressants[?] (e.g. Wellbutrin, Effexor)
• norepinephrine reuptake inhibitors[?] (not approved in the United States)
• are there any more?

Also despite controversy, alternative treatments for depression such as the herbal remedy St John's wort have gained popularity in recent years.