LSD (lysergic acid diethylamide) is one of the major drugs making up the hallucinogen class. LSD was discovered in 1938 and is one of the most potent mood-changing chemicals. It is manufactured from lysergic acid, which is found in ergot, a fungus that grows on rye and other grains.
LSD, commonly referred to as "acid," is sold on the street in tablets, capsules, and, occasionally, liquid form. It is odorless, colorless, and has a slightly bitter taste and is usually taken by mouth. Often LSD is added to absorbent paper, such as blotter paper, and divided into small decorated squares, with each square representing one dose.
The US Drug Enforcement Administration reports that the strength of LSD samples obtained currently from illicit sources ranges from 20 to 80 micrograms of LSD per dose. This is considerably less than the levels reported during the 1960s and early 1970s, when the dosage ranged from 100 to 200 micrograms, or higher, per unit.
Most users of LSD voluntarily decrease or stop its use over time. LSD is not considered an addictive drug since it does not produce compulsive drug-seeking behavior as do cocaine, amphetamine, heroin, alcohol, and nicotine. However, like many of the addictive drugs, LSD produces tolerance, so some users who take the drug repeatedly must take progressively higher doses to achieve the state of intoxication that they had previously achieved. This is an extremely dangerous practice, given the unpredictability of the drug.
The US National Household Survey on Drug Abuse (NHSDA) reports the nature and extent of drug use among the American household popula tion aged 12 and older. In the 1996 NHSDA estimates, the percentage of the population aged 12 and older who had ever used LSD (the lifetime prevalence rate) had increased to 7.7 percent from 6.0 percent in 1988. Among youths 12 to 17 years old, the 1996 LSD lifetime prevalence rate was 4.3 percent, and for those aged 18 to 25, the rate was 13.9 percent. The rate for past-year use of LSD among the population ages 12 and older was 1 percent in 1996. Past-year prevalence was highest among the age groups 12 to 17 (2.8 percent) and 18 to 25 (4.6 percent). The rate of current LSD use in 1996 for those aged 18 to 25 was 0.9 percent, and it was 0.8 percent for 12- to 17-year-old youths.