Although newspaper stories often talk about the discovery of a gene for condition x, y or z the reality is that most diseases are caused by the combination of a large number of genes working alongside environmental factors. Three studies by a multinational group of researchers - including some from the Institute of Psychiatry in London - analyzed the DNA of 10,000 people with schizoprenia and 20,000 unaffected people. It found that there were 30,000 common gene variations linked to schizophrenia. The same genetic patterns were also linked to bipolar disorder suggesting there may be a link between the two conditions.
You can read more about the genetics of schizophrenia and bipolar disorder at