The national debate over legalizing marijuana should be guided as much as possible by facts ("Stirring the pot," Nov. 12). Although marijuana is listed by the DEA as a "Schedule 1" drug — the same category as heroin — the notion that cannabis is as dangerous as heroin is false.

There is no scientific or medical evidence that supports lumping together marijuana and heroin. The 1972 decision to label marijuana as a Schedule 1 drug was heavily influenced by political considerations and was opposed by the American Medical Association. It was an administrative, bureaucratic decision that was not one supported by scientific or medical findings.

Methamphetamine and cocaine are much more addictive and dangerous than cannabis, yet they are listed as "Schedule 2" drugs. Alcohol and tobacco are both more addictive than cannabis and have a number of well-known negative health consequences, yet they are perfectly legal.

The unjustified classification of marijuana has for decades impeded genuine understanding of its actual risks and benefits. Rather than acting on the basis of fear and misinformation, we need to make informed decisions based on medical and scientific fact when grappling with the important social, medical and legal issues surrounding the use of cannabis.

Bradley Alger, Baltimore