Social anxiety disorder and marijuana use problems: the mediating role of marijuana effect expectancies.

BACKGROUND: Individuals with social anxiety disorder (SAD) appear particularly vulnerable to marijuana-related problems. Yet, mechanisms underlying this association are unclear.

METHODS: This study examined the role of marijuana effect expectancies in the relation between SAD and marijuana problems among 107 marijuana users (43.0% female), 26.2% of whom met Diagnostic and Statistical Manual for Mental Disorders-Fourth Edition criteria for SAD. Anxiety and mood disorders were determined during clinical interviews using the Anxiety Disorders Interview Schedule-IV-L (ADIS-IV).

RESULTS: Analyses (including sex, marijuana use frequency, major depressive disorder, and other anxiety disorders) suggest that SAD was the only disorder significantly associated with past 3-month marijuana problems. Compared to those without SAD, individuals with SAD were more likely to endorse the following marijuana expectancies: cognitive/behavioral impairment and global negative expectancies. Importantly, these expectancies mediated the relations between SAD status and marijuana problems.

CONCLUSIONS: These data support the contention that SAD is uniquely related to marijuana problems and provide insight into mechanisms underlying this vulnerability.