They Call Themselves Scientists?

One of the key points about the scientific method is that particular types of information are or are not valid within a conceptual framework. One of the types that is almost always tossed out on its ear is anecdotal evidence. At a recent press conference regarding the effects of marijuana use in children younger than 12, John Walters, director of National Drug Control Policy, had some criticism for Canada's decision to start clinical trials of marijuana derivatives:

The question was tied to a decision by Canada last month to approve the prescription drug Sativex, an oral spray that contains the active ingredient of marijuana, to treat the symptoms of multiple sclerosis.

He responded, "We believe that there's a clear distinction" between validated medical benefits and what he said could be "a bunch of ads where people testify that their mother, dying, smoked a joint and was saved, and that means marijuana is medicine."

On its face, not a bad point, at least in terms of my not having the Canadian data at hand. However, Director Walters's rigor regarding anecdotal evidence does not seem to hold when the evidence supports his conclusion (from the section of the article immediately before the previous quote):

The parents of a teenager who committed suicide last year were also at the news conference, and they linked their son's death to his marijuana use.

Tanya Skaggs, of Colorado Springs, Colorado, said, "He had a severe lack of judgment that was because of the marijuana, this destructive behavior was continuing," in the months leading up to his death.

I have a real problem with people using science to support politics becuase the science always gets mangled in the process. (Much the same reason that I think it is better for religion to stay separate from politics.) I find it interesting that those who claim to be using science to more rationally set policy are very often the ones who take a single scientific datum and react emotionally to it.

"The evidence is collectively indicating that there is a causal connection," says Neil McKeganey, PhD, professor of drug misuse at the University of Glasgow in Scotland.

McKeganey notes that scientists have not yet uncovered evidence linking marijuana use to the brain changes routinely seen in people who suffer from mental illness. "If we wait until we understand that mechanism, we will lose thousands of young people," he says. [Link]

That attitude pretty much says it all.