Professor Cyndi Weickert at Neuroscience Research Australia has made her biggest breakthrough in 30 years of studying schizophrenia relating to immune cells.

Professor Cyndi Shannon Weickert has been looking at human brain tissue for 30 years to better understand why her twin brother suffered schizophrenia, and she believes a recent breakthrough may be the answer.

Her research just published in scientific journal Molecular Psychiatry details how immune cells play a part in the underlying cause of schizophrenia in some patients.

Challenging the assumption that immune cells were independent of the brain is psychiatric illnesses, a new cell - the macrophage - was identified in the brain tissue of people with schizophrenia who show high levels of inflammation.

"The research suggests some of the pathology is not coming from the cells that are residents of the brain but in fact they could be coming from the immune cells themselves," Professor Weickert told AAP.

"Now we can have renewed interest in repurposing drugs that have been developed for inflammatory conditions to the extent that they will work for people suffering from schizophrenia," she said.

This is something that hits close to home for Professor Weickhert, given the entire reason she became a molecular biologist stemmed from watching her twin brother at 17 endure the side affects of medication that frequently had little to no affect.

After her brother was put into a state institution surrounded by silent sufferers in straitjackets, she describes his subsequent medical treatment as "zombifying", while he likened the medicine to "poison".

Her smart sibling who had so much potential in life was instead living out traumas which Professor Weickhert thought could be prevented with finely-tuned research.

"I just thought my God we have to get to the bottom of this horrible thing happening to a normal kid," Professor Weickert said.

Her research at Neuroscience Research Australia (NeuRA) initially employed new molecular techniques to look at three specific brain cells in 74 patients. This was then replicated, totalling about three or four hundred case studies.

The study encourages further collaboration between neuroscientists and immunologists, and sees added benefit in trialling safe anti-inflammatory therapies with existing medications.

Various sub-types of schizophrenia have been diagnosed for years, taking into account major life episodes, and drug use as potential cause. However these new findings could potentially lead to biologically-led diagnoses.

Similar to the way breast cancers have been studied on a molecular level, Professor Weickhert says the way forward in psychiatry is to study the brain's tissue.

"This is the biggest breakthrough and the most exciting thing I've dug up about the brain in all this time, I can see the path forward now and that's really exciting."