The Effects of Sex and Residual Cannabis Use on Emotion Processing: An Event-Related Potential Study

Cannabis use has been shown to affect processing of emotional facial expressions as measured by the P1 and P3 event-related potential (ERP) components. These components have been shown to be related to emotion processing in particular attention to emotion. Previous research also indicates that there are sex differences in how cannabis effects males and females as well as how they process emotion. This study examined the relationship between the effects of residual cannabis use and sex differences in 144 participants (F = 80) in a facial expression emotion processing task. Both the P1 and P3 ERP components were compared in male and female participants in noncannabis user, casual cannabis user, and heavy cannabis user groupings. The task involved implicitly, explicitly, and empathically identifying emotional expressions (angry, happy, neutral, and fearful) in male and females faces. There were differences between males and females in both the P1 and P3 ERP in relation to cannabis use. Males had a larger P1 than females with cannabis use and a smaller P3. Differences in the P1 were observed in both positive and negative emotion and between tasks in relation to cannabis use patterns. Differences in the P3 were seen in heavy male users for empathy happy and casual male users implicit angry when compared to females. These differences highlight the important of considering sex differences in regard to the effects of cannabis, in particular in emotion processing. Public Health Significance This study found significant differences in the processing of emotion in relation to cannabis use patterns between males and females. This suggests that when considering the implications of the effects of cannabis use it is important to address sex differences in particular in relation to emotion processing and emotion processing disorders such as anxiety, depression and PTSD.