Does social anxiety influence reporting of cannabis consequences? A differential item functioning analysis of the...

Undergraduates with social anxiety disorder (SAD) are at a heightened risk for experiencing cannabis-related consequences, despite using cannabis at similar rates as those without SAD. One possible explanation may be that there are systematic differences in how individuals with SAD respond to self-report measures of cannabis-related consequences, particularly for items relying on subjective appraisal. The present study conducted a differential item functioning (DIF) analysis on the Brief Marijuana Consequences Questionnaire (B-MACQ) to determine whether any items were biased toward undergraduates with clinically significant SAD symptoms. Undergraduates (N = 1,261; M_age = 19.33; 73.7% female; 68.7% white; 45.8% with clinically significant SAD symptoms) from six U.S. universities who reported past-month cannabis use completed an online survey assessing SAD, cannabis use, and cannabis-related problems. DIF analyses indicated that only one B-MACQ item functioned differently across groups, whereby students with clinically significant SAD symptoms were more likely than those without SAD to endorse the item, "I have felt anxiety, irritable, lost my appetite or had stomach pains after stopping or cutting down on marijuana use." After removing this item, an ANCOVA controlling for past-month cannabis frequency demonstrated that students with clinically significant SAD symptoms continue to report greater B-MACQ total scores than those without SAD. Findings indicate that one B-MACQ item demonstrated measurement bias and should be interpreted with caution when administering the measure to individuals with SAD. Yet even after accounting for this bias, students with clinically significant SAD symptoms reported heightened cannabis-related consequences, highlighting the need for interventions that concurrently address SAD and cannabis use.