The data for marijuana usage by different age groups over the past 20 years are shown in the figure.
The peak years for the percentage of marijuana users were 1979÷1982. Then use declined noticeably until about 1990 when it leveled off. For all years the use was highest in the 18÷25 year old group and lowest in the over 26 age group. Marijuana usage decreased in the 1980s, a period of continually stronger law enforcement. The drop in marijuana usage cannot be attributed to education or medical rehabilitation, because marijuana is a relatively benign substance. Increased education (as opposed to propaganda) about marijuana would encourage its use.
Marijuana comes from the hemp plant (Cannabis sativa). It raises the heart rate and lowers blood pressure. Its effects, which last 2÷6 hours, include euphoria, heightened sensitivity, perceptual changes, and increased appetite. High or repeated doses can produce paranoia, panic, and reduced motivation. Marijuana can cause psychological dependence and some tolerance. It is not addictive, but a withdrawal syndrome¸that includes irritability, depression, and insomnia¸is reported following abrupt cessation of use. However any individual adverse symptom appears in less than 3% of users.
The number of hospital emergency department drug mentions rose from 15,706 in 1990 to 40,183 in 1994 for marijuana/hashish. On a per 100,000 population basis, the number of mentions in 1994 was 17.5 for marijuana/hashish. There are no known deaths attributed to marijuana use.
Many people that have tried marijuana find the experience unpleasant and discontinue its use. Included in this group are those that experience paranoia and/or hallucinations. For those that continue use, the marijuana experience is almost uniformly described as being pleasant and relaxing. Marijuana as a trigger to violence seems never to have been reported by any user or researcher. The relationship is in the other direction. Marijuana is anti-criminogenic.
There are important medical uses of marijuana. It relieves nausea induced by AIDS and chemotherapy. It relieves the pressure causing glaucoma, and can reverse the effects of that disease. Taken with other drugs, 2÷5 joints per day of marijuana can prevent epileptic seizures. Multiple sclerosis can be reversed by smoking 4÷6 joints per day of marijuana. It can control muscle spasms and pain and return sexual potency to paraplegics and quadriplegics. Five to ten milligrams of tetradelta÷9÷tetrahydrocannabinol can reduce chronic pain where other pain killers fail. It also prevents migraine headaches and can cure atopic neurodermatitis. Some states have passed laws permitting the medical use of marijuana if prescribed by a medical doctor. However U. S. federal law takes supremacy, and the medically prescribed use of marijuana still is criminal, even in those states that permit its use.
Over the years, a number of official government reports have been issued giving the medical effects of marijuana. Francis L. Young, Chief Administrative Law Judge of the Drug Enforcement Administration (DEA) concluded in 1988 that marijuana is among the safest therapeutic substances known and is less hazardous than many common foods. He wrote: "The evidence in this record clearly shows that marijuana has been accepted as being capable of relieving the distress of great numbers of very ill people, and doing so with safety under medical supervision. It would be unreasonable, arbitrary, and capricious for the DEA to continue to stand between those sufferers and the benefits of this substance in light of the evidence." Nevertheless, Young's recommendations were rejected by John Lawn, the Administrator of the DEA, on the grounds that there have been no extensive large-scale controlled studies to demonstrate the effectiveness of marijuana. Of course, it is criminal to conduct such investigations.
The data on driving accidents, as I analyzed them, suggest that marijuana/hashish currently has about a 20% higher effect on driving accidents than does alcohol. It is not surprising that marijuana/hashish acts like alcohol, since both are depressants.
In the late 1980s about 400,000 arrests per year were for marijuana violations. The percentage dropped from 68% of all drug arrests in 1982 to a minimum of 24% in 1991. Since then it rose to 34% in 1994. In 1997, there were 640,000 arrests for marijumna violations in the United States. About 85% of these were for possession.