The brains of teenagers smoking cannabis daily for about three years showed significant structural changes affecting memory. Some of those changes appear very similar to those seen in the brains of schizophrenics.These youngsters also performed badly when tested on memory tasks, indicating poor memory functioning.As reported by Marla Paul for Northwestern University on Futurity;
This is the first study to target key brain regions in the deep sub-cortical gray matter of chronic marijuana users with structural MRI and to correlate abnormalities in these regions with an impaired working memory.
Working memory is the ability to remember and process information in the moment and—if needed—transfer it to long-term memory. Previous studies have evaluated the effects of marijuana on the cortex, and few have directly compared chronic marijuana use in otherwise healthy individuals and individuals with schizophrenia.
According to the lead study author Mathew Smith an assistant research professor in psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine;
“The study links the chronic use of marijuana to these concerning brain abnormalities that appear to last for at least a few years after people stop using it. With the movement to decriminalize marijuana, we need more research to understand its effect on the brain.”
But in contrast to these findings another study conducted at the Institute of Psychiatry at King's College London, has shown a genetic link between cannabis use and schizophrenia. Kate Kelland reports for Reuters that;
The results chime with previous studies linking schizophrenia and cannabis, but suggest the association may be due to common genes and might not be a causal relationship where cannabis use leads to increased schizophrenia risk.
"We know that cannabis increases the risk of schizophrenia. Our study certainly does not rule this out, but it suggests that there is likely to be an association in the other direction as well – that a pre-disposition to schizophrenia also increases your likelihood of cannabis use," said Robert Power, who led the study at the Institute of Psychiatry at King's College London.
But what become evident from both these recent studies is the clear connection between adolescent use of cannabis and the development of schizophrenia. Therefore it is important for parents to discourage their children from getting swept up in this growing wave of legal recreational use of marijuana. We need to educate ourselves and our children on the very real dangers and consequences of indiscriminate use of marijuana.
References:
Teen marijuana use linked with schizophrenia (Futurity-January 3, 2014)
Study finds genetic links between schizophrenia and cannabis use (Reuters-June 24, 2014)
Cannabis-Related Working Memory Deficits and Associated Subcortical Morphological Differences in Healthy Individuals and Schizophrenia Subjects (Schizophrenia Bulletin-December 15, 2013)
Genetic predisposition to schizophrenia associated with increased use of cannabis (Molecular Psychiatry-June 24, 2014)
