Marijuana legalization states have taken no steps to limit the potency of marijuana, which has increased sharply in recent years. A new study suggests this could create public health problems down the road as more users become addicted or otherwise impaired.
The study was conducted in the Netherlands, where marijuana is legally available through “coffee shops.” The researchers examined the level of delta-9-tetrahydrocannabinol (THC), the main intoxicant in marijuana, over a 16-year period.