Cannabis is a Class B drug that has been linked in previous research to psychosis
People carrying a specific gene may be more at risk of developing mental health problems from smoking cannabis, according to researchers A study from King’s College London found that cannabis smokers carrying the gene AKT1 had double the chance of developing a psychotic disorder and this increased up to seven-fold if they used the Class B drug daily.
The scientists, led by Dr Marta Di Forti, said their research could be used to advise people who are particularly at risk of the psychological side-effects. Previous research has shown a link between smoking cannabis and psychosis. There is also emerging data that cannabis exposure during adolescence may increase the risk of developing schizophrenia.
The team studied 489 patients who had had their first episode of psychosis and 278 healthy controls. They looked at the AKT1 gene which is involved in dopamine signaling and known to be abnormal in psychosis. They performed genetic tests on all volunteers, and assessed their use of cannabis. Dr Di Forti said: 'We found that cannabis users who carry a particular variant in the AKT1 gene had a two-fold increased probability of a psychotic disorder and this increased up to seven-fold if they used cannabis daily. 'Although using cannabis increases the risk of schizophrenia, most cannabis users come to no harm. It has therefore been suggested that those who develop psychosis may carry some genetic vulnerability. Our findings help to explain why one cannabis user develops psychosis while his friends continue smoking without problems. Such findings could also help to design health educational campaigns tailored to reach those young people at particular risk.'
Dr John Krystal, Editor of Biological Psychiatry says: 'While the AKT1 genotype does not rise to the level of a clinically useful test of the risk for cannabis psychosis, it does show that this source of psychosis risk has a genetic underpinning. This advance also points to cellular signaling mechanisms mediated by Akt1 as being relevant to the biology of cannabis psychosis. This may suggest research directions for novel therapeutics for cannabis psychosis.' The authors added that further research is needed before the findings can be clinically significant.
Source: Daily Mail UK