Source

Substance Abuse and Mental Health Services Administration. Risk and protective factors and initiation of substance use: results from the 2014 National Survey on Drug Use and Health. NSDUH Data Review. 2015.

https://www.samhsa.gov/data/sites/default/files/NSDUH-DR-FRR4-2014%20(1)/NSDUH-DR-FRR4-2014.pdf