Cannabis use and short memory effects
The cannabis consumers are frequently seen as not very bright individuals, if not completely dumb. In spite of this common stereotype, some studies carried on by Dr. Robert Tait and his collaborators at School of Psychology, University of Wollongong, Australia , showed that reality is slightly different.
To date, reviews on the long-term cognitive sequelae of cannabis use have examined a broad range of cognitive functions .*Memory problems* are frequently associated with cannabis use, in both the short- and long-term.
These studies evalutated memory function in cannabis users in the nontoxicated state with the aim of identifying the existence and nature of memory impairment in cannabis users and appraising potentially related mediators or moderators. To evaluate cognitive performance California Verbal Learning Test (CVLT) (immediate and delayed), Spot-the-Word test (STW), Symbol Digit Modality test (SDMT) and Digit Backwards (DB), were applied. Partecipants were divided in groups according to their consumption duration and quantity and were studied repeatedly for three times over a time span of 8 years.
First results showed significant differences between cannabis groups on CVLT (immediate and delayed) and SDMT. But after controlling for education, gender, gender × group and gender × wave, there were no significant between-group differences and only CVLT immediate recall reached adjusted statistically significant longitudinal change associated with changed cannabis use . Specifically, former heavy users improved their performance relative to remaining heavy users. Quitting cannabis use appears to recover the capacity for recall of information that has just been learned. No other measures of cognitive performance were related to cannabis after controlling for confounds.
*Cannabis use and cognitive function":
http://www.ncbi.nlm.nih.gov/pubmed/21749524
The chronic effects of cannabis on memory in humans: a review
http://www.ncbi.nlm.nih.gov/pubmed/19630708
Associated studies:
http://www.ncbi.nlm.nih.gov/pubmed/15205869
