Friday, May 09, 2008

More crap science from George Bush and co.

Today the mainstream media is full of a report released by the White House Office of National Drug Control Policy, which is headed up by John Walters, who doesn't even have a Ph.D., a man who has said, over the years, various highly stupid things which we don't need to get into here.

The report claims that "recent research" indicates various rather scary causual connections between marijuana use and depression/suicide in teens, and even goes so far as to say that marijuana use can lead to scizophrenia and "other forms of psychosis".

What an unbelievable load of crap. I can't believe we're paying this whole agency to produce these ridiculous terrifying reports that no self respecting peer reviewed journal would ever publish because they are just shoddy science.

This sort of thing would get me C's and D's at UW.

Meanwhile, more than 100,000 deaths are caused by excessive alcohol consumption each year.

Here's a one question survey: Guess how many deaths are caused by marijuana use every year.


Joe said...

Not sure that is entirely fair, Benjamin.

This is a report in the British Medical Journal, which is both respected and peer reviewed.

This is from the British Journal of Psychiatry.

I'm not a physician nor a psychiatrist. You might be quite right that it is a crock of crap, and I agree that there seems to be an overemphasis on tackling the use of this drug over others. But it is not the case that these kind of studies do not appear in respected peer reviewed journals.

Benjamin Ady said...


Note the *huge* difference between the language of the BMJ editorial as well as the BJP research article and the language of the report from the White House ONDCP

BMJ: "Establishing direction of causality is difficult and is most appropriately assessed in non-clinical samples, but a low incidence of the illness and the fact that most drug users take other drugs in addition to cannabis create methodological problems and explain the dearth of reliable evidence."

BJP: "Owing to the cross sectional nature of the study, associations do not necessarily reflect causal relationships".

See how careful they are about the huge difference between correlation and causality?

Now here's the White House ONDCP--the TITLE of the paper, for crying out loud, in a HUGE FONT AND ALL CAPS (that is, shouting at us):


This is absolutely crap science of the worst sort, and fear mongering to boot. There's only one sure way to demonstrate that teen marijuana use worsens depression. You have to take a sample of depressed teenagers, do some kind of reliable (that is, validated) depression measure for all of them, randomly assign them to a control group or an experimental group (they're not allowed to know which group they're in), have the experimental group use marijuana, have the control group *not* use marijuana (you'll have to take steps, as I said, to make sure participants don't know which group they're in), then do the reliable (that is, validated) depression measure again. If the difference between the pre and post scores is significantly larger for the experimental group than for the the control group (that is, if the depression of the experimental group has increased significantly more than the depression of the control group), *THEN* you accurately say "With XX% confidence we found that marijuana worsens depression in teenagers"

That's the slightly more technical version. The ... slightly more popular version is thus: If you find that teens who use marijuana are more depressed than teens who don't use marijuana, there are (at least) three possible explanations for the correlation: 1. Being depressed could *cause* marijuana use, 2. Using marijuana could *cause* depression, or 3. Both marijuana use and depression could be *caused* by some third variable (Like ... their parents are assholes, for instance)

Am I making sense?

Editors of peer reviewed journals would look at the white house report, were it submitted for publication, and in about 10 seconds they would round file it and go on to the next thing in their day.

Joe said...

Ah I get what you're saying now.

Benjamin Ady said...


thank you for saying so. I'm often slightly unsure of whether I'm managing to say what I *mean* to say or just muddying things more =)

You rock.

Joe said...

Sorry man, I got the wrong end of the stick, I thought you were suggesting there was no work on the subject. As you correctly say, correlation does not imply causation.