Please google things instead of saying "cite" if you are curious, since a lot of scientific studies show up, but here are the receipts on IQ.

Here's an old one where I got my original number: https://www.pnas.org/doi/10.1073/pnas.1206820109

Here's a recent one showing an average of 5.5 points: https://psychnews.psychiatryonline.org/doi/10.1176/appi.pn.2...

Yeah no, I am going to ask for a cite if you reference a study.

Looks like the first study is for adolescent-onset usage of cannabis and they were unable to show any long term effects for adult-onset users after cessation of use, even in this observational study.

This tracks with my general understanding of the literature, and it seems like this does not really apply to an adult who has substituted cannabis for alcohol.

Can you cite a source for your understanding of the literature?

At least a few studies disagree with you about adult onset, and it does appear that adolescent use amplifies the effects, but is not the only factor:

https://jamanetwork.com/journals/jamainternalmedicine/fullar...

https://www.nature.com/articles/tp2015201

https://www.sciencedirect.com/science/article/pii/S2352250X2...

The last one is a review article.

Not in a position to respond longer right now, but that last study you referenced is actually one of the ones I had in mind, in that there is not evidence in this literature review for long-term effects after cessation.

The first study there shows some evidence of performance decline after cessation, but they do not eliminate adolescent users. The second study was unable to distinguish brain structure for users that had ceased consumption from normal brains.

I definitely was not trying to suggest that there are no cognitive impacts on current users.

Oh, ok. I think we are in agreement - I didn't mean to suggest that there were long-term effects years after quitting, but that there are long-term effects of use - which perhaps I should have described as "effects of long-term use."

I agree that the jury is not in yet on whether there are long-term effects years after cessation except for adolescent use (and - by the way - old people: if you are over 70, smoking pot does appear to retard dementia and cognitive decline).

No, if you claim you bloody well cite. It's not on us to fill in your omissions.

Given that, your 2nd paper is interesting and supports you. The first seems (emphaisis: seems) to back up findings that most damage is done to the adolescent developing brain with cannabis, but still reading it.

Edit: 2nd paper doesn't seem to ask when cannabis use started so it's quite possible the damage was done in adolescence, not adulthood:

"Cognitive tests were conducted at ages 7, 9, and 11 using the Wechsler Intelligence Scale for Children-Revised and again at age 45 using the Wechsler Adult Intelligence Scale-IV. Additional neuropsychological tests were administered to measure the participants’ verbal learning, attention, memory, processing speed, and more"

so tested as pre-teens then at age 45.