“High school students in CASA’s survey who report having ever used marijuana are more likely than students who never used marijuana to report that they feel alone or isolated (26.7 percent vs. 19.9 percent), that they often feel very sad or depressed (27.9 percent vs. 14.0 percent) and that they think they will develop depression during their lifetime (41.0 percent vs. 25.4 percent).7

Source

Adolescent Substance Use: America’s #1 Public Health Problem," The National Center on Addiction and Substance Abuse at Columbia University (New York, NY: National Center on Addiction and Substance Abuse at Columbia University, June 2011), p. 46.
http://www.casacolumbia.org/a…