Benzodiazepine use in Chile: impact of availability on use, abuse, and dependence.

This study tested the hypothesis whether over-the-counter benzodiazepine availability influenced patterns of benzodiazepine use, abuse, and dependence in Chile. If over-the-counter availability represents a major risk factor leading to benzodiazepine substance use disorders, rates of abuse, and dependence would be significantly higher among over-the-counter benzodiazepine users than among prescription drug users. The study was a household survey of a stratified sample (N = 1,500) of the Santiago (Chile) population performed by trained interviewers. Data were collected by structured questionnaires on demographic characteristics, drug use, psychoactive substance use disorders, and other psychosocial variables. Past-year prevalence of benzodiazepine use was 31.4%, daily use of benzodiazepines for > or = 12 months, 5.9%, and subjects who met DSM-III-R criteria for dependence, 3.3%. Seventy-four percent of subjects obtained the benzodiazepine over-the-counter (always 45%; sometimes 29%). No subject acknowledged recreational benzodiazepine use or met criteria for benzodiazepine abuse. Use, long-term use, and dependence occurred equally frequently among both over-the-counter and prescription benzodiazepine users. Results suggest that although over-the-counter availability increases benzodiazepine use, it is not a major risk factor that leads to benzodiazepine abuse and/or dependence.