But harm falls disproportionately on the less-intelligent, that was my point in bringing it up in the first place. If you are intelligent and disciplined you are better positioned to use drugs in a way that doesn't lead to harm.

Edit: From https://www.irp.wisc.edu/publications/fastfocus/pdfs/FF32-20...

> Recent research using 1992 to 2011 National Health Interview Survey data combined with data from the National Vital Statistics System indicates that the recent drug overdose epidemic—driven largely by prescription opioids and heroin—has implications for life expectancy differences by education level. Specifically, while drug overdose deaths have grown for all education groups, those with less than a high school education lost the most years of life. Overdose deaths now represent a substantial share of the widening inequality in life expectancy by education level.

>When Ronald Graham, a concerned friend and fellow mathematician, bet him $500 that he couldn’t stay off his drug of choice for a month, Erdős accepted and easily won the challenge. When the 30 days was up, Erdős said to Graham, “You’ve showed me I’m not an addict. But I didn’t get any work done. I’d get up in the morning and stare at a blank piece of paper. I’d have no ideas, just like an ordinary person. You’ve set mathematics back a month.”

This quote is hilarious, and I find it interesting that there's a difference in intelligence between drug users and non users. My gut feeling is that there would be no significant difference.

I will note that most drug use does not impact intelligence negatively. Of course it can if abused to a great enough degree as that will significantly alter neural function but this also depends on the specific mechanisms of the substance.

Dr. Carl Hart is a great example of this. He's been a recreational heroin user for 5 years and is a tenured professor of neuroscience at Columbia.

https://en.m.wikipedia.org/wiki/Carl_Hart