A reader emails:

Regarding your section "Lies, Damned Lies And Statistics" on your weblog today, you quoted Bob Weiner as saying that THC was the second leading cause of car crashes. I did some quick research and this certainly appears to be false. In fact, the studies specifically find that THC is only statistically significant if used in combination with another drug.

See the following links:

Link 1

Link 2

The definitive review would appear to be this one, because it appeared in Epidemiologic Reviews:

Link 3

Unfortunately, this journal does not have full-text articles (or even abstracts) available on-line to that date.

What, a (former) government official lie about effects of illegal drugs? I'm shocked, shocked...

Agreed all around, but in college I was rather shocked that several people I knew actually believed they drive better on dope. Granted, it was the 70s, but still...

Heh. They think that, because they tend to drive slower. Slower doesn't necessarily make better. It does, however, make for really embarrassing cop stops, like when a friend of mine was pulled over for going 15 miles an hour in a 55.

When I was in college I would drive back and forth from Houston to Miami during breaks. 20 joints rolled 1/2 tobacco & 1/2 weed made that trip much easier to handle (worked out to about 1 per hour). It didn't get me stoned, it didn't make me sleepy, and it helped me keep my attention focused on the dull, monotonous road.

Nah that attitude still persists Ken cause most the people I hang out with now insist that smoking makes them drive better. I used to say that also until one time I came up to a 4-way stop, with stop signs, and sat there waiting for the light to turn green. Didn't snap out of it till the person behind me honked their horn.

Lots of drunk drivers think it's enough to be more careful "after they've had a few"

Pot's a hallucinogen... It causes you to see thinks that aren't there, that can be just as dangerous as the way a depressant like alcohol slows your reflexes.

MarkD writes:

>Lots of drunk drivers think it's enough to be
> more careful "after they've had a few"

With all due respect, I think you are confounding subjective reports of perception (ie: "drunk drivers think it's enough...") with what a subject actually does (ie: drives more, or less, safely).

The evidence is very strong (and observed repeatedly) that drivers who have used cannabis alone simply do not have the high accident rates as drivers who have used alcohol, except in naive subjects (subjects who don't know what effects to expect from the substance) and very high dosages exceeding ordinary use levels.

See http://www.sciencedaily.com/releases%5C1999%5C03%5C990325110700.htm

for a reasonably well reported metanalysis of driving studies.

>Pot's a hallucinogen... It causes you to see
>thinks that aren't there, that can be just as
>dangerous as the way a depressant like alcohol
>slows your reflexes.

With all due respect, I've never heard of any credible neuroscientist who classifies cannabis as a hallucinogen in ordinary dosages. In extremely high dosages, most any chemical, including alcohol, tobacco, caffeine and cannabis, can be somewhat hallucinogenic of course.