POT HOLES: Legalizing marijuana is fine. But don’t ignore the science on its dangers.
Excerpt: But I am also a neuroscientist, and I can see that the story is being oversimplified. The debate around legalization — which often focuses on the history of racist drug laws and their selective enforcement — is astoundingly naive about how the widespread use of pot will affect communities and individuals, particularly teenagers. In our rush to throw open the gate, we might want to pause to consider how well the political movement matches up with the science, which is producing inconveniently alarming studies about what pot does to the adolescent brain. ... As watering a flooded field is moot, widespread cannabinoid activity, by highlighting everything, conveys nothing. And amid the flood induced by regular marijuana use, the brain dampens its intrinsic machinery to compensate for excessive stimulation. Chronic exposure ultimately impairs our ability to imbue value or importance to experiences that truly warrant it. In adults, such neuro-adjustment may hamper or derail a successful and otherwise fulfilling life, though these capacities will probably recover with abstinence. But the consequences of this desensitization are more profound, perhaps even permanent, for adolescent brains. Adolescence is a critical period of development, when brain cells are primed to undergo significant organizational changes: Some neural connections are proliferating and strengthening, while others are pared away. ... It’s not surprising, then, that heavy-smoking teens show evidence of reduced activity in brain circuits critical for flagging newsworthy experiences, are 60 percent less likely to graduate from high school, and are at substantially increased risk for heroin addiction and alcoholism. They show alterations in cortical structures associated with impulsivity and negative moods; they’re seven times more likely to attempt suicide. Recent data is even more alarming: The offspring of partying adolescents, specifically those who used THC, may be at increased risk for mental illness and addiction as a result of changes to the epigenome — even if those children are years away from being conceived. The epigenome is a record of molecular imprints of potent experiences, including cannabis exposure, that lead to persistent changes in gene expression and behavior, even across generations.