Irish researchers discover a link between adolescent cannabis use and psychotic conditions. Katie Belle reports… IF you smoke cannabis you are running a very real risk of developing schizophrenia in later life. That’s the rather alarming news that has just emerged from the Royal College of Surgeons in Ireland (RCSI). So telling are the findings that the report has been carried in the prestigious Nature Neuropsychopharmacology journal. The study, which was conducted by Dr Aine Behan of the Department of Physiology, found that the brain changes physically when it comes into contact with cannabis. And these changes are associated with the development of schizophrenia and psychosis. More particularly, cannabis interacts with a gene called the COMT gene, which results in the physical changes in certain areas of the brain. “This is the first study to show that the combined effects of the COMT gene with adolescent cannabis use causes physical changes in the brain regions associated with schizophrenia,” said Dr Behan. “It demonstrates how genetic, developmental and environmental factors interact to modulate brain function in schizophrenia and supports previous behavioural research which has shown the COMT gene to influence the effects of adolescent cannabis use on schizophrenia-related behaviours.” Chemical Messenger The COMT gene provides instructions for making enzymes which break down a specific chemical messenger called dopamine. Dopamine acts like a bridge between one nerve cell and another, where its main job is to conduct signals and make sure that they get to where they need to be. It acts predominantly in the brain’s pleasure centre; hence the attraction of cannabis and other drugs which are designed to elicit a pleasurable effect. Adolescent cannabis use and its interaction with particular forms of the COMT gene have been shown to cause the physical changes in the brain and are now linked with the development of schizophrenia. The three areas of the brain assessed in this study were found to show changes in cell size, density and protein levels. “Increased knowledge on the effects of cannabis on the brain is critical to understanding youth mental health, both in terms of psychological and psychiatric wellbeing,” said Dr Behan. It’s easy to see why cannabis is such a popular drug. It acts on the system almost immediately and brings about a sense of intoxicated euphoria. Wellbeing is increased and this can be accompanied by giddiness. Some users say that the drug can have the effect of speeding time up. A very short space of time can feel like an hour. Sights, smells and tastes are all enhanced. Colours appear brilliant. Everything can appear hilarious and raucous laughter can be the order of the day for some users. Up to now, it has been known that use of the drug can result in an impairment in short-term memory, as well as an increase in heart rate. Many users report feeling somewhat groggy and a bit forgetful, but not a lot else. This new study will put a whole new look on a very popular recreational drug.