http://oas.samhsa.gov/2k5/MJreferrals/MJreferrals.htm
"A recent study found that while the prevalence of marijuana use remained stable between 1991-1992 and 2001-2002, the prevalence of marijuana abuse or dependence diagnoses increased significantly during this time. A recent report examined marijuana treatment admissions between 1992 and 2002 and found that between these years the rate of substance abuse treatment admissions reporting marijuana as their primary substance of abuse increased 162 percent."
