Who is becoming hallucinogen dependent soon after hallucinogen use starts?

This study, based upon epidemiological survey data from the United States (U.S.) National Household Surveys on Drug Abuse (NHSDA) from 2000 to 2001, presents new estimates for the risk of developing a hallucinogen dependence syndrome within 24 months after first use of any hallucinogen (median elapsed time ∼12 months). Subgroup variations in risk of becoming hallucinogen dependent also are explored. Estimates are derived from the NHSDA representative samples of non-institutionalized U.S. residents ages 12 and older (n = 114,241). A total of 2035 respondents had used hallucinogens for the first time within 24 months prior to assessment. An estimated 2–3% of these recent-onset hallucinogen users had become dependent on hallucinogens, according to the NHSDA DSM-IV computerized diagnostic algorithm. Controlling for sociodemographic and other drug use covariates, very early first use of hallucinogens (age 10–11 years) is associated with increased risk of hallucinogen dependence (p < 0.01). Excess risk of developing hallucinogen dependence was found in association with recent-onset use of mescaline; excess risk also was found for recent-onset users of ecstasy and of PCP. This study's evidence is consistent with prior evidence on a tangible but quite infrequent dependence syndrome soon after the start of hallucinogen use; it offers leads that can be confirmed or disconfirmed in future investigations.