PEOPLE suffering schizophrenia have more molecules in their brains specifically designed to respond to marijuana, ground-breaking research by Melbourne scientists has shown.
With schizophrenia sufferers abusing cannabis at twice the rate of the general population, the study by the Mental Health Research Institute has given hope that anti-psychotic medications could target both mental illness and addiction.
The study and results from research in Germany have shown the first molecular links between schizophrenia and cannabis use.
While people with schizophrenia mainly abuse alcohol and nicotine, their rate of cannabis use is at least twice that of the general population and up to 12 times higher for other illicit drugs.
Researcher Suresh Sundram said the human brain had special molecules that responded specifically to cannabinoids – compounds produced naturally by the body and also when cannabis is smoked or eaten.
Dr Sundram said a post-mortem study of the brains of schizophrenia sufferers showed the special molecules were more concentrated in an area of the brain believed to play a crucial role in the development of both schizophrenia and substance abuse.
"This wasn't changed in people who didn't have schizophrenia," he said.
Sundram says more research is needed to determine the significance of the finding.
"We don't know whether it's something associated with the disease or whether it's something the body has done in response to the disease," he said.
Sundram said further work by the institute on the anti-psychotic drug clozapine suggested it could help people with schizophrenia control their addictions.
The drug, reserved for people who did not respond to standard treatment, targeted the molecules in the region of the brain involved in addiction and schizophrenia, he said.
"People with schizophrenia that use substances have a much worse outcome compared with those who don't use substances.
"It doesn't stop them from getting better, it just makes their road to recovery much more difficult."
Sundram said the number of people who became psychotic after smoking cannabis was small.
"However, we have no way of knowing who's vulnerable and who's not vulnerable.
"Anyone who smokes cannabis runs the risk of developing schizophrenia."
Source: The Australian
Date: 27 March 2004