75% of the authors are affiliated with other institutions, only 3 are with the National Institute on Drug Abuse.
NIDA itself is well-grounded. There have been some instances where they take a more conservative stance given uncertainty in results, but this is still a national scientific institute - not DARE or the DoJ.
Finally, the paper is on PMC: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5426185/ - why do you disagree with their conclusion?