Although now legal in Colorado and Washington, marijuana is the most widely used illegal drug in America and its popularity is growing.
This is according to a large, new, nationwide survey from the substance abuse and mental health services administration.
"In 2012, nearly 19 million people were past month users of marijuana," said SAMHSA Administrator Pamela Hyde.
That's up from 14.5 million in 2007.
Heroin use has also risen significantly while alcohol remains prevalent.
Slightly more than half of Americans say they drink alcohol.
"135 million people in America are drinkers," said Hyde.
According to the survey, 81% of those who took their first sip of alcohol last year were under the legal age of 21.
Overall, teenage abuse of alcohol, tobacco and prescription pain killers is down or stable.
Experts urge parents and caregivers to continue talking to their kids about the dangers of drugs and alcohol even starting the conversation as early as age 9.
"The longer we can keep children and youth from taking that first drink, the better it is for them physically and the better our chances are in prevent them from having adult problems with drinking later in life," said Hyde.
The report was compiled with survey data from more than 70,000 people.
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