"Teen users are at significantly higher risk of developing an addictive disorder compared to adults, and the earlier they began using, the higher their risk. Nine out of 10 people who meet the clinical criteria for substance use disorders involving nicotine, alcohol or other drugs began smoking, drinking or using other drugs before they turned 18. People who begin using any addictive substance before age 15 are six and a half times as likely to develop a substance use disorder as those who delay use until age 21 or older (28.1 percent vs. 4.3 percent)."
Source
"Adolescent Substance Abuse: America's #1 Public Health Problem," National Center on Addiction and Substance Abuse at Columbia University, June 2011, p. 2.
