On an average day, 1.2 million full-time college students in the U.S. (ages 18 to 22) drank alcohol and 703,759 smoked marijuana, according to a new report by the Substance Abuse and Mental Health Services Administration (SAMHSA). The report also shows that on an average day, 239,212 part-time college students (ages 18 to 22) drank alcohol and 195,020 used marijuana. The report differentiated full-time and part-time college students by their college enrollment status.