Does cannabis use affect prospective memory in young adults?

The aim of the present study was to examine prospective memory impairments associated with cannabis use in young adults. An independent measures design utilising pre-existing groups of users and non-users was employed in which an opportunity sample of 90 undergraduates studying at universities in the north east of England participated. The number of prospective memory failures reported on the Prospective Memory Questionnaire and the number of location-action combinations correctly recalled during a video-based prospective memory task were measured. The number of strategies used to assist memory, level of anxiety and depression, and use of alcohol, nicotine and any other recreational drugs in addition to cannabis were also measured and controlled during the analysis. Analysis revealed no significant differences in the number of self-reported prospective memory failures; however, cannabis users recalled significantly fewer location-action combinations than non-users in the video-based prospective memory task. The findings from the present study suggest that cannabis use has a detrimental effect on prospective memory ability in young adults but users may not be aware of these deficits.