In addition to the illicit drug stream, huge amount of legal drugs gets diverted to users. Check out the growth in the number of prescriptions written for opioids. The manufacturers and crooked doctors have a good measure of culpability. Legal prescriptions have gone up 4X in 25 years. Notice the correlation of deaths to LEGAL prescriptions.
I understand the growth of prescriptions. Feds came in and said treat chroic pain, hurt many solders in 15 years of WOT, ...