Legal Weed

The Atlantic has a piece by Jonathan Caulkins "Legal Weed Didn't Deliver On Its Promises.*" Most of the piece is for subscribers, but you can find the full text here. I had been hearing for years that marijuana had steadily grown stronger, but I never paid much attention. 

Back in the '90s, the average daily pot user was consuming roughly 32 milligrams of THC a week. Today, it's more than 2,000 milligrams of THC a week.

That is not purely about marijuana potency.  Comparative measurement is difficult, because 70s marijuana was often half seeds and stems. Domestic strains were weak, so smugglers from Colombia and other foreign sources could adulterate their product without much worry or competition.  What else were you gonna do? So simple quantity was up, pipe by pipe, joint by joint. And as near as we can tell, that product was about 4% THC, which held until the early 90s, but current Colorado dispensary is about 19%. Lastly, before legalisation more of the tokers were weekend users. Daily use has increased year over year.

The numbers are shocking, and yet this is what happens when frequency, potency, and quantity all rise in tandem. For some consumers, high potency itself encourages more frequent use by delivering a stronger effect.

Medical science can’t yet clarify the effects of long-term use of 300-plus milligrams of THC a day, because this consumption pattern is new. Most controlled studies work with short-term exposure to smaller doses, often in the 20-to-50 milligram range, and observational studies that followed users for years were examining a drug—low-strength, infrequently used cannabis—that barely exists anymore.

The effect of drugs and alcohol on schizophrenia became the central focus of Dr. Alan Green up at Geisel Medical School.  I knew him slightly and attended several of his presentations before I semi-retired in 2017.  (Dartmouth provided our medical staff for decades.  Good training for them.) I wanted to see if he had anything new in the research on stronger marijuana, but alas, he died a few days after I completely retired in 2020. I never knew.  It shows how quickly we can drop out of being in the know, doesn't it? I must post something of his soon.

For our purposes here, Green established pretty definitively that THC increased the likelihood of schizophrenia. Combining it with family data he saw an even stronger connection with close relatives, suggesting that adding THC on top of a genetic predisposition is a particularly dangerous combo. The estimate was that if you were male and did not use marijuana before age 27 you were probably out of the woods, 30 for females.  We would all look over the tops of our eyeglasses on that one, because who starts at 27, having never tried the stuff before? Alan recognised that and would acknowledge it gracefully, yet used it to illustrate the level of unknown risk people were taking when they were young.

I used to say that after those ages the general risk of harm was low.  I don't feel confident in saying that anymore.

I couldn't find anything from Dartmouth-Hitchcock on stronger marijuana and schizophrenia, but at 60x the previous average amount, I doubt that things are um, better. It could in fact be catastrophically worse, and at that number I would expect that.  However, I will not violate my own rule rejecting scientific claims that begin with "well it just stands to reason." I consider it likely but have no direct evidence.

*Also on the front page is "Is There Anything Trump Won't Blame on DEI?" by Jonathan Chait.  I didn't read it, silently countering in amusement Is there anything The Atlantic in general, and Jonathan Chait in specific, won't blame on Trump? Questions are fun when you turn them around. You can see a lot just by looking, as Yogi Berra probably didn't say.