Evidence of discrepant data regarding trends in marijuana use and supply, 1985-1988.

Between 1985 and 1988, the estimated number of current marijuana users (i.e., use within the past 30 days) in the United States declined 36%, based on self-report data from the National Household Survey on Drug Abuse. During the same time period, estimated nondomestic production of marijuana available for consumption in the United States increased 58% and domestic production increased 119%, while there was no clear-cut trend in prices. Reports of marijuana use associated with emergency room visits more than doubled in these years. The reasons for these apparent discrepancies in the data regarding the supply and use of marijuana are unknown. The possible causes of change in these and other measures of illicit drug use are examined because they form the basis for assessment of the efficacy of the recently proposed 1989 National Drug Control Strategy.