70 % of Americans 2012 used Marijuana regularly in 2007 , survey finds . Marijuana is legal in two states , while 20 more allow medical use . Although it 's only a slight increase , the real contrast exists between 2012 and 2007 , when 5.8 % of Americans said they regularly used weed . Heroin use is up 70 % since age 12 or older , according to the survey .
70 % of Americans 2012 used Marijuana regularly in 2007 , survey finds . Marijuana is legal in two states , while 20 more allow medical use . Heroin use is up 70 % since age 12 or older , according to the survey .