Some emergency departments will screen everybody for substance use. It isn’t that big a challenge; you simply add a basic questionnaire on the subject to your intake paperwork. A number of brief instruments have been validated through extensive research. The World Health Organization offers the AUDIT, which uses ten multiple-choice questions to identify risky drinking practices, and the ASSIST, which includes drugs and tobacco as well as alcohol.
Some clinicians screen first with a simple question. Example: “in the past 3 months, has there been an occasion when you’ve consumed more than 5 drinks? (4 for women).” Turns out a positive response correlates very strongly with unhealthy drinking, and triggers further questioning.
I’m not aware of something comparable for other drug use. Still, simply asking for the number of occasions on which the patient has used drugs other than alcohol will usually get a result. You may be asked to clarify what you mean by ‘drugs’, but that starts the discussion.
When questioning someone directly, it’s a good idea to request their permission. As in: “Mind if I ask a couple questions about your drinking practices? Could be helpful to us.” Most folks will consent, if reluctantly.
Can the patient lie, or minimize? Sure. But this isn’t a full evaluation of a substance disorder. We’re just looking for the possibility of hazardous use.
Using a validated screen such as the AUDIT or ASSIST provides objective support for the notion that the problem may merit further attention. You can share the results and interpret their meaning. Some clinics screen via computer. That may elicit more honest responses. For some reason, people are more open with the machine than a live human being.
Above all, avoiding any suggestion that you’re judging the responses. The less confrontational you can be, the less defensiveness you’ll encounter.