The analysis of 2017 data suggests shifting patterns of drug use, with cocaine and amphetamines positivity surging in some areas of the county and marijuana positivity rising sharply in states with newer recreational use statutes. Prescription opiate positivity rates declined dramatically on a national basis.

https://www.securitymagazine.com/articles/89026-us-workforce-drug-use-at-highest-level-in-a-decade