A clinical trial being led by Queensland researchers is looking into whether the tropical fruit known as the mangosteen could offer a gentler treatment for schizophrenia.

Key points: Range of antioxidants are found within the skin of the mangosteen

Range of antioxidants are found within the skin of the mangosteen 150 people will be studied over six months to see the effects from the rind

150 people will be studied over six months to see the effects from the rind Hopes it could offer a gentler treatment to other traditional medications

Mangosteen has long been used in traditional medicine in South-East Asia, and now Australian researchers hope to prove that its antioxidants could ease psychosis and other symptoms.

Present day medication for schizophrenia can have some unpleasant side effects, and researchers are hoping that if their trials prove positive, the fruit could be used as a milder treatment for the mental illness.

Mangosteens are a tropical evergreen fruit from Indonesia, resembling a passionfruit on the outside, with a dark thick skin.

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The Queensland Brain Institute's John McGrath, who is leading the research, said a range of "wonderful antioxidants" could be found within the skin of the mangosteen.

"These compounds may reduce inflammation and treat free radicals, which can be a side effect of diseases and inflammation," Professor McGrath said.

"So I've spoken to people from Indonesia and Malaysia and from India, where their grandmothers would make up teas or extracts from mangosteen skins and it would be given to them for upset tummies and a whole range of things."

Researchers will study 150 people over six months to see what effect the use of antioxidants from mangosteen rind might have on hallucinations, delusions, moods and energy levels.

'Medications can make you like a zombie'

The research has flowed on from earlier work which showed that antioxidants found in fish oil could help treat schizophrenia.

"We're targeting people with recent onset disorder and we're trying to improve their outcomes," Professor McGrath said.

"It may well be that they will have lower symptoms of hallucinations or less distressing delusions, for example.

"And we have a serious lack of safe and side-effect-free and effective medications— that's what we're trying to do here."

David Nicholls, from the Northern Territory, has lived with his mental illness for 52 years.

"I've had schizophrenia since birth … there's paranoia, there's anxiety, voices," he said.

He said he had experienced a range of side effects from medications, including muscle spams, weight gain and impotence.

"Some medications make you like a zombie," he said.

But Mr Nicholls said there was one benefit to his schizophrenia, it was "very good for creativity".

"You're always thinking out of the box," he said.

"I like my schizophrenia. I do a lot of art and write stories.

"Maybe if they had a medication that could either dull my voices right down or get rid of them totally, because I've had 52 years of day and night voices and they've really taken their toll."