Total Harm Scores for Various Drugs, using data from the 2010 study: "Drug harms in the UK: a multi-criteria decision analysis." Dr. Mark J. Perry, a professor of economics and finance in the School of Management at the Flint campus of the University of Michigan.

A top Drug Enforcement Administration agent repeatedly refused to admit Wednesday that any drug—including crack, methamphetamine and heroin—was more harmful or addictive than marijuana.



Instead, administrator Michele Leonhart asserted that "all illegal drugs are bad."



Was she right to equate them?



Not according to the most recent and well-regarded study on the physical damage drugs can cause.



The study placed heroin, crack and meth far above marijuana, both in terms of harm to self and harm to others. Cocaine and tobacco were also ranked as more harmful than marijuana. Alcohol was ranked most dangerous.



Yet here is Leonhart's exchange at the House Judiciary Subcommittee hearing Wednesday with Democratic Rep. Jared Polis, first reported by Raw Story:



POLIS: "Is crack worse for a person than marijuana?"



LEONHART: "I believe all illegal drugs are bad,"



POLIS: "Is methamphetamine worse for somebody's health than marijuana?...Is heroin worse for somebody's health than marijuana?"



LEONHART: "Again, all drugs."



POLIS: "Yes, no, or I don't know?... If you don't know this, you can look this up. As the chief administrator for the Drug Enforcement Agency, I'm asking a very straightforward question."



Watch the full exchange below:



(See the Total Harm Scores For Various Drugs chart in a larger size at the blog of Mark J. Perry, a professor of economics and finance at the University of Michigan.)