Schizophrenia linked to sunlight exposure

A University of Queensland researcher has suggested schizophrenia may be caused by a lack of sunlight exposure on pregnant women.

As a result, low maternal vitamin D may subtly alter brain development, leaving the offspring at increased risk of developing schizophrenia as an adult. The major source of vitamin D is via the action of sunlight on skin.

Associate Professor John McGrath from UQ's Department of Psychiatry says this could explain why there is a higher incidence of 'schizophrenia births' in Europe and North America in late winter and early spring.

'It may also explain why there's a peak in schizophrenic births in Queensland every three to four years, which seems to occur at the same frequency in which the El Ni?o system periodically brings overcast weather,' Dr McGrath said.

Dr McGrath, who is based at the Queensland Centre for Schizophrenia Research and neurobiologist Associate Professor Alan Mackay-Sim from Griffith University tested this hypothesis by depriving pregnant rats of UV light or vitamin D in their food.

'The brains of the rats' offspring looked like the brains of people with schizophrenia - the baby rats had enlarged ventricles or fluid-filled cavities,' Dr McGrath said.

'If low prenatal vitamin D is a risk factor for schizophrenia, then this gives us some hope of one day preventing schizophrenia.'

'A lot more work needs to be done, because too much vitamin D can cause birth defects. However I hope that one day supplements for pregnant women or even sunlamps could cut the incidence of this mental disorder,' he said.

Schizophrenia is a group of brain disorders that affects a person's ability to think clearly, leading to hallucinations, delusions and poor planning. It affects 1 in 100 Australians and contributes substantially to the global burden of disease.

For more information contact Associate Professor John McGrath on 07 3271 8595 or Peter McCutcheon at UQ Communications on 07 3365 1088 or 0413 380012