Marijuana concentrates such as shatter, butter or glass have THC concentrations as high as 90 percent. The same high levels are found in edible cannabis products sold in Colorado, packaged to look like popular candy bars and particularly appealing to children.
And despite the perception that marijuana is not addictive the way opiates or nicotine are, Potee said that 17 percent of those who start using it as adolescents develop addiction. For teens who use marijuana every day, the addiction rate is 30 to 50 percent.