Cannabis may affect the processing of emotional facial expressions differently in men and women

New research suggests that cannabis use may have different effects on men and women’s ability to process emotional information. The findings have been published in the journal Experimental and Clinical Psychopharmacology.

“I have been researching the effects of cannabis on emotion processing for nearly 10 years,” said study author Lucy J. Troup, a reader in psychology at the University of the West of Scotland.

“In light of living and researching at the time in Colorado, the first state to legalize recreational cannabis, I was particularly interested in what that actually meant in terms of its effects on individuals and society. I became interested in the polarization of views on cannabis and the conflicting body of scientific — and a great deal of non-science based literature — supporting either position.”

Troup’s previous research has indicated that cannabis use was associated with a depressed ability to “implicitly” identify and empathize with emotions. But the new study sought to take a closer look at the differences between men and women.

The researchers used electroencephalogram (EEG) to monitor the electrical brain activity of 80 female and 64 male undergraduate students while they completed a facial expression emotion processing task, in which they were asked to identify neutral, happy, angry, and fearful faces.

Among female participants, the use of cannabis was unrelated to neural responses to faces. But among male participants, the researchers observed cannabis-based differences in brain activity related to visual attention in emotion processing.

The findings “suggest that early attentional processes may be affected more in male cannabis users than females,” the researchers wrote in their study.

“There is a complex relationship between the effects of cannabis use and its effects on emotion processing. There appears to be a significant effect of individual differences, in this case biological sex, on its effects,” Troup told PsyPost.

“This may be made even more complex by differences in males and females in relation to mood disorders and the interaction between cannabis use, biological sex and possible sex-based predispositions for sub-clinical depression.”

But there is still much to learn about how cannabis impacts emotional processing and the brain in general.

“As with all things cannabis, there is good, bad and ugly. We need more research to properly begin to evaluate its effects rather than anecdotal personal and political non-fact based data,” Troup said.

“For every scientific paper published to say it’s good, there is also one to say it’s bad or ugly. Despite the difficulties in looking at individual differences, it is crucial that we include these in our endeavors to make a full and accurate evaluation of the effects of cannabis.”

The study, “The Effects of Sex and Residual Cannabis Use on Emotion Processing: An Event-Related Potential Study“, was authored by Lucy J. Troup, Jeremy A. Andrzejewski, and Robert D. Torrence.