EDITORIAL: ‘A false assumption’

The lazy stoner has a celebrated niche in Hollywood, embodied in the likes of Jeff Spicoli, Harold and Kumar, Pedro de Pacas and “the Dude.” Turns out, though, these comedic portrayals often mimic the unfortunate reality of heavy pot smokers.

As researchers delve deeper into the consequences of marijuana use, they are finding that the drug saps smokers of drive and motivation.

In Saturday’s Wall Street Journal, Susan Pinker in her Mind &Matter column details studies conducted by Canadian researchers who found that rats injected with the active ingredient in marijuana preferred taking the easy route with minimal reward to solving a tougher problem with a more fruitful bounty.

“Whether they were workers or slackers to begin with, even small amounts of THC made them all slackers,” Catharine Winstanley, a psychology professor at the University of British Columbia, told Ms. Pinker.

A study by a team from the University of College London and published this month in the journal Psychopharmacology found a similar pattern in humans.

“The study of 17 adults showed that inhaling cannabis with THC alone … induces people to choose an easy task more often, eschewing the harder one that offered four times the payoff,” Ms. Pinker writes.

If there’s a bright side for marijuana users in these findings, Ms. Pinker notes that “THC didn’t impair the rats’ ability to perform, only their willingness to try.” In addition, the human study found “the subjects’ apathy didn’t persist after the high wore off.”

All this is worth considering as state voters face Question 2 on the November ballot. It would allow Nevadans older than 21 to possess up to an ounce of pot for recreational use.

Supporters downplay the potential public health consequences of legalizing the drug. But Ms. Pinker points out that the potency and ingredients included in the pot sold in many marijuana stores varies widely and that there is “no consistency in testing, standards or labeling.” Levels of THC are increasing and “few people know what effect that has on their brains,” she writes.

“Thinking that it’s harmless, that you can smoke cannabis and you’ll be fine, is a false assumption,” said Michael Bloomfield, a University College London psychiatry professor. “THC alters how willing you are to try things that are more difficult.”

Legalizing dope in the Silver State may be a boon for White Castle and a slew of well-connected insiders who will walk away with lucrative retail licenses. Not so much for those whose ambition and enterprise will evaporate in a cloud of smoke.