Research shows poor heart health is to blame for a 25 year-life expectancy gap between those with schizophrenia and the general population.

Australians with schizophrenia die 25 years earlier than the general population, according to a new study.

The gap in life-expectancy has been labelled a "preventable tragedy" and led to calls for urgent national action.

A research paper by researchers at the University of Sydney and published in the Medical Journal of Australia, shows people with this mental illness mainly die because of poor heart health.

"People with schizophrenia and psychosis die early in life mainly from heart attacks, heart disease, and strokes due to untreated hypertension and high cholesterol, and high rates of obesity and smoking," said lead author, psychiatrist Professor Tim Lambert of the University of Sydney Collaborative Centre for Cardiometabolic Health in Psychosis (ccCHiP).

Prof Lambert says a lack of co-ordinated care between hospitals, community mental health services, GPs and other primary health care professionals is to blame.

"There is no mystery about how to manage these diseases and risk factors," he said.

The report also says the use of antipsychotic drug colzapine elevates the risk of poor health because of its link with weight gain and dyslipidemia, a condition where there is an abnormal amount of fats in the blood plasma.

The facts on schizophrenia and heart health:

• One in three illness-related deaths among people with schizophrenia is due to cardiovascular disease
• People with schizophrenia have up to a three-fold increased risk of both coronary artery disease and sudden cardiac death
• Up to 88 per cent have untreated dyslipidaemia
• Up to 62 per cent have high blood pressure.