The teen brain is especially susceptible to the harms of THC

The amount of THC in cannabis plants is much higher than 30 years ago

a picture of a concentrated cannabis product

Concentrated cannabis products, produced by extracting cannabinoids from the plant, can have a THC potency as high as 95 percent.

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Ask thousands of teens whether frequent use of certain substances brings a high risk of harm, and they mostly nail it: a majority say yes for cigarettes, alcohol, cocaine and heroin. But there’s one substance that many skip over — cannabis.