Marijuana Abuse

What are the effects of marijuana abuse?

Marijuana abuse can have effects on the body immediatley after smoking it which can last from 1 to 3 hours. If marijuana is consumed in food or drink, the short-term effects begin more slowly, usually in 1/2 to 1 hour, and last longer, for as long as 4 hours. Smoking marijuana deposits several times more THC into the blood than does eating or drinking the drug.

Within a few minutes after inhaling marijuana smoke, an individual\s heart begins beating more rapidly, the bronchial passages relax and become enlarged, and blood vessels in the eyes expand, making the eyes look red. The heart rate, normally 70 to 80 beats per minute, may increase by 20 to 50 beats per minute or, in some cases, even double. Drug abuse of other illict drugs mixed with marijuana abuse can make the effect much greater.

As THC enters the brain, it causes a user to feel euphoric - or "high" - by acting in the brain\'s reward system, areas of the brain that respond to stimuli such as food and drink as well as most drugs of abuse. THC activates the reward system in the same way that nearly all drugs of abuse do, by stimulating brain cells to release dopamine.

Someone who partakes in marijuana abuse may experience pleasant sensations, colors and sounds may seem more intense, and time appears to pass very slowly. The user\'s mouth feels dry, and he or she may suddenly become very hungry and thirsty. His or her hands may tremble and grow cold. The euphoria passes after awhile, and then the user may feel sleepy or depressed. Occasionally, marijuana abuse produces anxiety, fear, distrust, or panic.

Heavy marijuana abuse impairs a person\'s ability to form memories, recall events and shift attention from one thing to another. THC also disrupts our central nervous system with coordination, balance, posture, coordination of movement, and reaction time. Through its effects marijuana abuse can cause accidents. Studies show that approximately 6 to 11 percent of fatal accident victims test positive for THC. In many of these cases, alcohol is detected as well.

In a study conducted by the National Highway Traffic Safety Administration, a moderate dose of marijuana alone was shown to impair driving performance; however, the effects of even a low dose of marijuana abuse combined with alcohol abuse were markedly greater than for either drug alone. Driving indices measured included reaction time, visual search frequency (driver checking side streets), and the ability to perceive and/or respond to changes in the relative velocity of other vehicles.  Marijuana abusers who have taken high doses of the drug may experience hallucinations, delusions, and depersonalization - a loss of the sense of personal identity, or self-recognition.

Information released by the National Institute on Drug Abuse

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