Attention, stoners. Put down the enormous sandwich and listen to this one: an intensive study of more than 1000 New Zealanders has found that regular cannabis use can be linked to memory loss and even a drop in IQ, and academics from around the world have come out to back the study.
The study followed 1037 Kiwis born in 1972-1973 over the course of 27 years — from a physical exam when they were 13-years old, right through to their late-30s and early-40s.
The study found that those who used cannabis in their teens and kept using it regularly through adolescence and into adulthood experienced cognitive memory impairment and decline by the time they were 38.
The researchers undertook an extensive background study to rule out any other factors influencing the results, and found data that indicated that the results were, in fact, accurate:
Poor education was ruled out as a contributing factor to lower cognitive function, as those who experienced poor marks in their studies due to cannabis use also included those who finished high school, and the effects of cannabis use found to be more severe in users who had a longer history with the drug.
Scientists also observed a "dose response relationship" between the use of cannabis and the decline in cognitive ability that could not be attributed to other factors like alcohol, tobacco and even schizophrenia.
Professor Wayne Hall with the University of Queensland Centre for Clinical research said of the study:
This prospective study greatly strengthens the case for regular cannabis use being a cause of cognitive decline by mid adulthood (age 38) in young people, especially who began to use cannabis in their teens and who persistently used throughout adolescence and into adulthood. Its findings add to the case for preventive public health education to reduce adolescent initiation and use of cannabis.
While Professor Robin Murray, a professor of psyhciatric research at Kings College London said:
“There are far fewer studies on its effect on minor psychiatric illness or on everyday life. However, there are a lot of clinical and educational anecdotal reports that cannabis users tend to be less successful in their educational achievement, marriages and occupations. It is of course part of folk-lore among young people that some heavy users of cannabis (my daughter callers them stoners) seem to gradually lose their abilities and end up achieving much less than one would have anticipated. This study provides one explanation as to why this might be the case.
Is this study going to make you put down the bong?