What Cues Do Laypeople Use to Detect Alcohol and Cannabis Intoxication?

Alcohol and other drug use is common in Australia, yet laypeople struggle to detect intoxication in others via observation. We examined cues laypeople use to detect alcohol and cannabis intoxication to explore whether knowledge (in)accuracy may account for intoxication detection difficulties.

Participants (N = 467; 77.7% female) completed a survey assessing familiarity with/use of alcohol and cannabis. Participants reported the cues they use to detect whether a person is intoxicated with alcohol and cannabis and rated the difficulty of such detection. Researchers assessed reported cues for accuracy and organised them into descriptive categories. Participant characteristics were examined as predictors of cue accuracy.

Alcohol intoxication detection was viewed as easy, while difficulty ratings for cannabis intoxication detection varied. Most reported cues to alcohol and cannabis intoxication were accurate. However, non-responses were common across both substances. Participants provided more cues-including accurate cues-to alcohol intoxication compared to cannabis intoxication. Cannabis consumption on a 'monthly'/'less than monthly' basis was associated with greater cue accuracy, and participants who viewed cannabis intoxication detection as difficult reported less accurate cannabis cues.

Accurate assessment of intoxication is essential in many high-risk contexts (e.g., healthcare, criminal justice, road and workplace safety). Our findings suggest that while laypeople can provide some accurate cues to alcohol and cannabis intoxication, substantial knowledge gaps exist-especially for cannabis. Education about an extensive range of cues to intoxication may improve intoxication detection in these contexts.