There are some issues with the study design, but this may be of interest to some of you:
'In order to examine the link between psychosis and creativity, psychiatrist Szabolcs Kéri of Semmelweis University in Hungary focused his research on neuregulin 1, a gene that normally plays a role in a variety of brain processes, including development and strengthening communication between neurons. However, a variant of this gene (or genotype) is associated with a greater risk of developing mental disorders, such as schizophrenia and bipolar disorder.
In this study, the researchers recruited volunteers who considered themselves to be very creative and accomplished. They underwent a battery of tests, including assessments for intelligence and creativity. To measure creativity, the volunteers were asked to respond to a series of unusual questions (for example, "Just suppose clouds had strings attached to them which hang down to earth. What would happen?") and were scored based on the originality and flexibility of their answers. They also completed a questionnaire regarding their lifetime creative achievements before the researchers took blood samples.'
More here:
http://www.medicalnewstoday.com/articles/165522.php