To the Editor:

A June 1 letter said that our 1991 Harvard survey of oncologists and medical marijuana found that most respondents favored prescribing THC pills over smoked marijuana. Actually, only 13 percent of the doctors favored the pills, while 44 percent favored smoking and 43 percent found them equally effective.

We appreciate that your May 25 editorial cited our work, but want to reinforce that our survey did not establish the drug's medical value. We asked for doctors' opinions, and even expert opinion is no substitute for experimental data. Unfortunately, definitive experiments required by the Food and Drug Administration have not been done, in part because the National Institute on Drug Abuse has been using its monopoly over research marijuana to hinder studies.

Such tests could not only resolve the question of efficacy, but also explore means of administration other than smoking, like vaporizers.

Rick Doblin
Mark A.R. Kleiman
Belmont, Mass., June 4, 2002
The writers are, respectively, president of the Multidisciplinary Association for Psychedelic Studies and director of the drug policy analysis program, University of California at Los Angeles.