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Definition: morphine from The Penguin Dictionary of Psychology

Named after the minor Greek deity Morpheus, the god of dreams and the son of the god of sleep, a powerful narcotic derived from the opium poppy. It is the principal alkaloid of opium; its primary action is as a depressant producing euphoria, drowsiness and relief from pain. Its use as an analgesic is limited by the development of increasing tolerance for the drug and the ease with which drug dependency develops.

Summary Article: morphine
From The Columbia Encyclopedia

principal derivative of opium, which is the juice in the unripe seed pods of the opium poppy, Papaver somniferum. It was first isolated from opium in 1803 by the German pharmacist F. W. A. Sertürner, who named it after Morpheus, the god of dreams. Given intravenously, it is still considered the most effective drug for the relief of pain.

See also drug addiction and drug abuse.

Effects and Uses

Morphine, a narcotic, acts directly on the central nervous system. Besides relieving pain, it impairs mental and physical performance, relieves fear and anxiety, and produces euphoria. It also decreases hunger, inhibits the cough reflex, produces constipation, and usually reduces the sex drive; in women it may interfere with the menstrual cycle.

Morphine is highly addictive. Tolerance (the need for higher and higher doses to maintain the same effect) and physical and psychological dependence develop quickly. Withdrawal from morphine causes nausea, tearing, yawning, chills, and sweating lasting up to three days. Morphine crosses the placental barrier, and babies born to morphine-using mothers go through withdrawal.

Today morphine is used medicinally for severe pain, cough suppression, and sometimes before surgery. It is seldom used illicitly except by doctors and other medical personnel who have access to the drug. It is injected, taken orally or inhaled, or taken through rectal suppositories. Methadone treatment has been useful in curing morphine addiction.


Morphine was first used medicinally as a painkiller and, erroneously, as a cure for opium addiction. It quickly replaced opium as a cure-all recommended by doctors and as a recreational drug and was readily available from drugstores or through the mail. Substitution of morphine addiction for alcohol addiction was considered beneficial by some physicians because alcohol is more destructive to the body and is more likely to trigger antisocial behavior. Morphine was used during the American Civil War as a surgical anesthetic and was sent home with many wounded soldiers for relief of pain. At the end of the war, over 400,000 people had the “army disease,” morphine addiction. The Franco-Prussian War in Europe had a similar effect.

In 1906 the Pure Food and Drug Act required accurate labeling of patent medicines and tonics. Various laws restricting the importation of opium were enacted, and the Harrison Narcotics Act (1914) prohibited possession of narcotics unless properly prescribed by a physician. Despite legislation, morphine maintained much of its popularity until heroin came into use, it in its turn believed to be a cure for morphine addiction.


See publications of the Drugs & Crime Data Center and Clearinghouse, the Bureau of Justice Statistics Clearinghouse, and the National Clearinghouse for Alcohol and Drug Information.

The Columbia Encyclopedia, © Columbia University Press 2018

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