antidepressant(redirected from tetracyclic antidepressant)
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antidepressant,any of a wide range of drugs used to treat psychic depressiondepression,
in psychiatry, a symptom of mood disorder characterized by intense feelings of loss, sadness, hopelessness, failure, and rejection. The two major types of mood disorder are unipolar disorder, also called major depression, and bipolar disorder, whose sufferers are
..... Click the link for more information. . They are given to elevate mood, counter suicidal thoughts, and increase the effectiveness of psychotherapypsychotherapy,
treatment of mental and emotional disorders using psychological methods. Psychotherapy, thus, does not include physiological interventions, such as drug therapy or electroconvulsive therapy, although it may be used in combination with such methods.
..... Click the link for more information. . Before the introduction of such drugs in the late 1950s, most patients with major depression had no recourse but hospitalization; only 45% improved after one year. In contrast, 80%–90% of such patients can expect significant relief from depression with one of the medications now prescribed.
Antidepressants act on the flow of the neurotransmitters epinephrineepinephrine
, hormone important to the body's metabolism, also known as adrenaline. Epinephrine, a catecholamine, together with norepinephrine, is secreted principally by the medulla of the adrenal gland.
..... Click the link for more information. , serotoninserotonin
, organic compound that was first recognized as a powerful vasoconstrictor occurring in blood serum. It was partially purified, crystallized, and named in 1948, and its structure was deduced a year later.
..... Click the link for more information. , and norepinephrinenorepinephrine
, a neurotransmitter in the catecholamine family that mediates chemical communication in the sympathetic nervous system, a branch of the autonomic nervous system.
..... Click the link for more information. across neural synapsessynapse
, junction between various signal-transmitter cells, either between two neurons or between a neuron and a muscle or gland. A nerve impulse reaches the synapse through the axon, or transmitting end, of a nerve cell, or neuron.
..... Click the link for more information. . Common antidepressants include monamine oxidase inhibitors (MAOIs) such as isocarboxazid (Marplan), tricyclics such as imipramine (Tofranil) and amitriptyline (Elavil), and the newer selective serotonin reuptake inhibitors (SSRIs) as fluoxetine (Prozac) and sertraline HCL (Zoloft). Venlafaxine (Effexor) inhibits both serotonin and norepinephrine reuptake.
The choice of antidepressant often has more to do with its side effects (variously sedation, constipation, hypotension, tachycardia, weight gain, sexual dysfunction) than efficacy, as they are generally regarded to be equally effective. The newer drugs, especially SSRIs, are tolerated better and are currently by far the most widely prescribed, but SSRIs also appear to be less effective in children and teenagers and may cause some of them to become suicidal.