Total US
According to the National Survey on Drug Use and Health (NSDUH), in 2008-2009, an estimated 13.37% of young people in the US aged 12 through 17 had used marijuana in the past year, falling to 12.29% in 2015-2016. The NSDUH also estimates that, in 2008-2009, an estimated 7.03% of young people in the US aged 12 through 17 had used marijuana in the past month, dropping to 6.75% in 2015-2016.

"In these initial investigations, we found no evidence that I-502 enactment, on the whole, affected cannabis abuse treatment admissions. Further, within Washington State, we found no evidence that the amount of legal cannabis sales affected cannabis abuse treatment admissions.

"The bulk of outcome analyses in this report used the within-state approach to focus on identifying effects of the amount of legal cannabis sales. We found no evidence that the amount of legal cannabis sales affected youth substance use or attitudes about cannabis or drug-related criminal convictions.

Limitation on Federal Interference With Implementation of State Medical Marijuana Laws: In December 2014, the federal budget for FY2015 was enacted, containing this provision:

Uruguay Legalizes Marijuana

"All recent policy documents state that the Dutch drug policy has two cornerstones - and this was confirmed by the Minister of Health, Welfare and Sport during the major drug debate in the House of Representatives in March 2012: to protect public health and to combat public nuisance and drug-related crime (TK 24077-259; TK Handelingen 69-28 maart 2012).

As of June 27, 2018, a total of 30 states plus the District of Columbia and Guam have what are called "effective" state medical marijuana laws, and one more state has created an academic program which may in the future help that state's patients.

Marijuana Tax Act of 1937: "Marijuana essentially became illegal in 1937 pursuant to the Marijuana Tax Act.³⁹ The use of marijuana required the payment of a tax for usage; failure to pay the tax resulted in a large fine or stiff prison time for tax evasion.⁴⁰ Drug prohibition was elevated to another level by targeting 'marijuana,' a plant that had never demonstrated any harm to anyone.⁴¹