Dear Dr Nina: Is there a link between cannabis and schizophrenia?
Our resident GP answers your medical queries in our weekly column.
A. Cannabis is one of the most commonly used drugs in the Western world. Evidence may be mounting that there are some health benefits to certain compounds of cannabis in certain conditions but this does not mean that it should be accessible to all without any concern for use. Cannabis is addictive. It can cause harm and is not a healthy substance.
Cannabis use is associated with increased incidence of anxiety, depression, amotivation syndrome, psychosis and schizophrenia. Major concern exists around the effects of cannabis on the teenage brain. Adolescent brains continue to change and grow and this is a time of great vulnerability to peer behaviour and influence.
The drugs available today are much stronger than the joints smoked by the Hippies of the 60’s and they can have permanent and devastating affects on the developing brain. Research shows that those who have a tendency towards psychosis are at a much higher risk of schizophrenia if they smoke cannabis particularly from their teen years. Scientists have identified two genes, which if present, further increase the risk up to seven times.
Cannabis also contains chemicals that are carcinogenic and can damage the lungs. Chronic smokers often develop a cough and bronchitis. Those who are addicted may need to smoke daily. Chronic users may be less motivated to attend school, college or work. Withdrawal is real and can include irritability and anger, sleep disruption, changes in appetite, depression and anxiety.
Cannabis is not the clean harmless drug that some would have you believe. It should be avoided especially in those with a personal or family history of mental health disorders.