Schizophrenia is more common in developed countries than poorer nations, but it is less widespread than previously thought.
These findings are from a Queensland Centre for Mental Health Research (QCMHR) report, published in the American-based journal Public Library of Science Medicine.
The report debunks a popular textbook definition that schizophrenia will affect 10 in every 1000 people no matter where patients live.
It says this rate is too high and more likely, between seven and eight in 1000 people, although this varied between sites.
Poorer countries also had more women with the illness than men.
The University of Queensland's Professor John McGrath, who led the research team, said the 21-page-report was the biggest and most comprehensive survey of schizophrenia rates around the globe.
His team collected 188 schizophrenia studies dating from 1965 to 2002 from 46 countries.
The group was funded by Queensland Health and US-based private health foundation the Stanley Medical Research Institute.
Professor McGrath, a UQ Professor of Psychiatry and QCMHR's Director of Epidemiology said the study would help health care planners see the bigger picture for the illness.
"Health budgets look at 'dollar per disability avoided. . . Health care planners need to know prevalence rates in order to allocate staff and funds," Professor McGrath said.
Schizophrenia is a group of brain disorders with symptoms such as hallucinations, delusions, disorganised communication, poor planning and reduced motivation.
Professor McGrath said he believed schizophrenia varied from region to region.
"Our data shows that the incidence and prevalence of schizophrenia varies much more around the world than previously acknowledged.
"My hunch is that the subtypes of schizophrenia vary between countries.
"Maybe the mix of illnesses we see here in Australia are different to the mix they get in Mumbai or Zambia or Tokyo."
He said to explain the results his team would try to match up new cases with current case data from the same sites and same times to help answer prognosis and illness duration questions.
The report is a companion to an earlier study by the same team on the number of new cases of schizophrenia worldwide.
It revealed that schizophrenia affected more men than women, more migrants than native-born citizens and was more common in cities than urban/rural areas.