More fun with DAWN

I was browsing through the DAWN report, and I came across the somewhat startling notation that marijuana was the 2nd most implicated illicit drug in drug-related suicide attempts.
Wow, I thought — who are all these people who are trying to commit suicide by marijuana? It’s a pretty tough challenge since nobody has ever died from an overdose of marijuana. It would be like committing suicide by drinking water. Oh, wait, you actually can overdose from water (you’d have to drink almost a gallon all at once), while you can’t fatally overdose from marijuana.
But of course nobody is actually attempting suicide by bong. The way DAWN works is that if you swallow a bottle of sleeping pills and smoke a joint, that’s a marijuana-related suicide attempt. Or if you smoked a joint yesterday and today you jump off a bridge, that’s a marijuana-related suicide attempt.
It’s really hard to understand how DAWN has any meaning at all. Let’s go to the DAWN report:

Suicide Attempts
DAWN estimates 121,585 (CI: 108,955 to 134,215) ED visits for drug-related suicide attempts in 2004 (Table 15).
It is important to remember that DAWN includes only those suicide attempts that involve drugs, but these attempts are not limited to overdoses. Also included are persons who attempt suicide by other means (e.g., by gun) when drugs are involved. Excluded are suicide attempts not involving drugs (e.g., by gun alone) and those documented as something other than an attempt (e.g., suicide ideation, gesture, thought, and so forth).
Nearly two-thirds of ED visits for drug-related suicide attempts involved multiple drugs (64%) (Table 16). Alcohol was the most frequently implicated drug and was involved in nearly a third (31%) of the ED visits for drug-related suicide attempts. Since DAWN excludes visits for adults when alcohol is the only drug, the role of alcohol in suicide
attempts is probably larger. The most frequent illicit drugs were cocaine (11% of visits) and marijuana (8% of visits), but the margins of error for the illicit drugs are quite large and the numbers are relatively small when compared with the pharmaceuticals.

There’s no indication as to whether they count you if your head explodes from reading the DAWN report.