The only wide-spread health problems we ever solved as a species were solved through medication (vaccines, antibiotics, etc). Heart disease, obesity, diabetes continue to be wide spread in spite of efforts to contain them.

Meanwhile smoking has been controlled through tight regulation and negative PR.

There's nothing preventing us from treating substance abuse as both and indeed it's likely more effective.

> Meanwhile smoking has been controlled through tight regulation and negative PR.

"Legalise drugs" does not mean provide them for free to anyone who asks with no controls at all on their supply or use.

smoking hasn't been controlled through "tight regulation", it's been controlled through the public health measure of price increase.