"Illicit drug use in 2011 varied by the educational status of adults aged 18 or older, with the rate of current illicit drug use lower among college graduates (5.4 percent) than those with some college education (10.4 percent), high school graduates (8.9 percent), and those who had not graduated from high school (11.1 percent)."
Source
Substance Abuse and Mental Health Services Administration, Results from the 2011 National Survey on Drug Use and Health: Summary of National Findings, NSDUH Series H-44, HHS Publication No. (SMA) 12-4713. Rockville, MD: Substance Abuse and Mental Health Services Administration, 2012, p. 23.
http://www.samhsa.gov/data/NS…
