What is schizophrenia?

Schizophrenia is a poorly understood group of mental disorders that disrupt the way in which the brain functions. Researchers are making progress in understanding the causes of this disabling disorder and it is now known that genetic factors play a role. Further, there is evidence that the disruption of early brain development may be an implication and that early cannabis use is also a risk factor.

It is a myth that people affected by schizophrenia have multiple personalities – confused thinking, delusions and hallucinations are the true signs of the illness. These symptoms can be controlled or eliminated with the right medication and community support, however this takes time.

Many people eventually make a full recovery from schizophrenia, but some have persistent symptoms. The average life expectancy of those with the illness is 10 years less than other people, because of increased physical health problems and a higher rate of suicide.

QBI research

The Queensland Brain Institute (QBI) is home to some of the most cutting-edge schizophrenia research in the world. Psychiatrists at the Institute are studying the triggers for schizophrenia and working to alleviate the factors that lead to the illness through improved public health messages and better treatments.

Most recently, a study of 3,800 people born in a Brisbane hospital in the early 1980s revealed that young people who use cannabis for extended periods have an increased risk of psychotic symptoms, such as schizophrenia. The research included 228 sets of siblings, making it the largest study of its kind ever undertaken.

“Looking at siblings is a type of natural experiment – we found the same links within the siblings as we did in the entire sample. The younger you are when you started to use cannabis – the greater the risk of having psychotic symptoms at age 21,” said lead researcher Professor John McGrath.

Earlier research projects have confirmed a number of other factors, such as low prenatal vitamin D and advanced paternal age, can increase a person’s risk of schizophrenia. In recent years, QBI’s Associate Professor Tom Burne and Associate Professor Darryl Eyles have demonstrated that a developmental vitamin D (the sunshine hormone) deficiency induces long-term changes in brain development and behaviour in animal models, and in 2009 researchers discovered that low levels of vitamin D at birth doubled a person’s chances of having schizophrenia in later life.

Further, the investigators have found that the older a person’s father, the more likely the child is to develop the symptoms of the illness.

“We have begun to accumulate evidence that there are increased risks of delaying fatherhood just as there are increased risks of delaying motherhood,” explained Associate Professor Burne.

The researchers are now focusing their efforts on trying to understand the mechanisms by which these risk factors lead to long-term changes in the way our brains work.