Driving Under The Influence of Cannabis Edibles is De Facto Legal

As states struggle with what to do about marijuana impaired driving, a new study from Johns Hopkins University makes things even more complicated. Study subjects consumed cannabis by eating it rather than smoking it, after which the research team assessed whether grossly impaired subjects would meet the legal standard of 5 ng/ml of blood THC.

The results were both surprising and disturbing, as I explain in my latest Washington Post Wonkblog.

Author: Keith Humphreys

Keith Humphreys is the Esther Ting Memorial Professor of Psychiatry at Stanford University and an Honorary Professor of Psychiatry at Kings College Lonon. His research, teaching and writing have focused on addictive disorders, self-help organizations (e.g., breast cancer support groups, Alcoholics Anonymous), evaluation research methods, and public policy related to health care, mental illness, veterans, drugs, crime and correctional systems. Professor Humphreys' over 300 scholarly articles, monographs and books have been cited over ten thousand times by scientific colleagues. He is a regular contributor to Washington Post and has also written for the New York Times, Wall Street Journal, Washington Monthly, San Francisco Chronicle, The Guardian (UK), The Telegraph (UK), Times Higher Education (UK), Crossbow (UK) and other media outlets.