In essence, brain scans of highly creative people and those who suffer from schizophrenia show striking similarities.
You can read the BBC piece here: http://news.bbc.co.uk/1/hi/10154775.stm
We are, of course, used to the notion of the tortured genius, and it may be worth noting that a popular creative writing technique is to just close our eyes and listen to 'the voice within'. I have used this approach to good effect, on occasion, when a clear voice will come through and tell its story. In my opinion, when this does work, the stories themselves have a different quality and arrive whole, with little plot or narrative editing required.
I used to travel regularly between the West Country and London; so regularly that I'd trained myself to see travelling time as writing time. One time, I looked at the cover of a train mag and saw a tiny photo of green fields. From there, I hopped from Green Hills to Silent Hills. Then I closed my eyes and listened for that elusive voice from the depths of my imagination. I didn't stop to question what was coming or from where it had been influenced, I just waited and listened, as my pen hovered.
The Silent Hills arrived over the course of the journey, in free flow. The protagonist's voice was there from the start and my only real effort lay in keeping pace with him and writing down his words. When we pulled into Paddington, I ran to the Underground so I could sit down again and pick up the thread.
The story was published in Issue 2 of the Black Market Review and is available online:
The Silent Hills was also published by Musa Publishing as an ebook Oct 14th 2011 - Oct 13th 2014.