(1) Among entire NSDUH sample; (2) represents NMPR/no cannabis, cannabis/no NMPR, both NMPR/cannabis, or no use of either (not shown); (3) represents alcohol only/no cannabis, cannabis only/no alcohol, both alcohol/cannabis, or no use of either (not shown). Estimates are weighted, and therefore adjust for population-level demographic changes.
Source: 2003 and 2013 National Survey on Drug Use and Health (NSDUH, 2003 and 2013).