Is LSD addictive?

LSD does not produce compulsive drug-seeking behavior. Addiction to hallucinogens is rare, although poly-drug addicts (people who are addicted to several drugs) frequently abuse hallucinogens as well. Because LSD users develop extreme tolerance to LSD rapidly, the drug cannot be abused for more than a few consecutive days, preventing the kind of physical and psychological dependence associated with other drugs. This tolerance usually goes away after a week or so of abstinence from the drug.