I don't think it directly causes it, but can contribute to the severity of the psychosis.
This link has some info that might help you understand a little more:
Take out the space between health and central; it seems to star it out if you put them together.
It is unlikely that stress alone will cause Schizophrenia, though it is often a factor in the onset and course of the disorder. For example, a person may have a genetic/biological predisposition towards Schizophrenia, a lot of stress that builds up over time or even a single traumatic event could trigger the onset of Schizophrenia. Patients with Schizophrenia often experience worse symptoms such as hallucinations and delusions while under stress. Schizophrenia is often comorbid (occurring at the same time) with Depression and Anxiety too, and one reason for this relationship may be stress involved with these mood disorders that exacerbates schizophrenic symptoms. Likewise, Anxiety can also be caused by things such as impaired social skills or paranoid delusions associated with Schizophrenia.