Impact of Marijuana Use on Self-Rated Cognition in Young Adult Men and Women

Background and ObjectivesMarijuana (MJ) is a widely used substance that has been shown to impair cognition in laboratory settings. There is a growing number of medical MJ dispensaries and state policies permitting the use of MJ in the United States. This study is a naturalistic study that explores the association of same day MJ use on self-rated cognition in young adult men and women. MethodsForty-eight (n=48) young adults (22 F; mean age=22.3) participated. After a baseline assessment, participants made daily phone calls to study staff over the next 3 weeks. Cumulative minutes of MJ use in the last 24-hours were assessed. Demographic information collected and self-ratings of cognitive impairment were assessed using six questions about areas of difficulty thinking each day. ResultsThere was a significant relationship between greater number of minutes of MJ use and higher levels of self-rated cognitive difficulties (b=.004; SE=.001; p<.006). There was no main effect of gender (b=1.0; SE=.81; p<.22). Planned evaluation of the interaction between gender and minutes of MJ use was not significant statistically, suggesting a similar relationship between minutes of MJ use and cognitive difficulties among women compared to men (p<.54). Conclusions and Scientific SignificanceThere is an association between current and heavy MJ use and self-perceived cognitive ability in both males and females. These findings reveal important information regarding one consequence of MJ use that has real-world meaning to young adult smokers. (Am J Addict 2015;24:160-165)