It's all about a filter we have in our heads, it seems: the thalamus. What schizophrenics and healthy highly creative people share is low density of dopamine receptors in the thalamus, which act as filter for incoming information. Normal people have many more of such dopamine receptors, filtering a lot of inputs and are hence less sensible but also more stable. Highly creative people and schizophrenics have less and hence filter little, what makes their brains to process much more information for good or bad.
Örjan de Manzano et al., Thinking Outside a Less Intact Box: Thalamic Dopamine D2 Receptor Densities Are Negatively Related to Psychometric Creativity in Healthy Individuals. PLoS ONE 2010. Open access.
Also discussed at Science Daily.
It is interesting because it gives some adaptative meaning to the genetics and epigenetics behind schizophrenia, as being highly creative is surely an adaptative trait.
I wonder if it offers some hope of treating schizophrenia by positivizing this attribute instead of mere chemical straight jackets, that is all psychiatrists can offer now. I've just seen too many lives ruined by this plague and the horribly arrogant and highly inefficient psychiatric handling of it.
It is also interesting because in the latest paper on Neanderthal genetics (Green 2010), they have found that some of the genetic regions exclusive to our species, H. sapiens, are related with mental conditions such as schizophrenia and autism, suggesting that maybe these traits offer also great potential rather than just a handicap (in which case they would have been selected against long ago, I presume).