"Five primary substances of abuse accounted for 96 percent of all substance abuse treatment admissions in 2007: alcohol, opiates (including heroin and prescription painkillers), marijuana, cocaine, and methamphetamine. Criminal justice system referral admissions were more likely than all other referral admissions to report primary alcohol abuse, primary marijuana abuse, and primary methamphetamine abuse and less likely to report primary opiate abuse. The high rate of criminal justice system referral admissions younger than 18 years old may have contributed significantly to the high rate of admissions with marijuana as a primary substance of abuse."

Source

The TEDS Report, "Substance Abuse Treatment Admissions Referred by the Criminal Justice System," Office of Applied Studies, SAMHSA (Arlington, VA: August 2009, p. 2.
https://ntrl.ntis.gov/NTRL/da…