PTSD and Psychotic Symptoms - Relationship between PTSD and Psychotic Symptoms
The researchers also found evidence that the more PTSD symptoms a person  was experiencing, the greater the likelihood that they would also  experience positive psychotic symptoms. 
To take their study a step further, the researchers also looked at what  traumatic events were most commonly related to the experience of  psychotic symptoms. They found the following to be most strongly  connected:
 •Being involved in a fire, flood, or natural disaster
•Seeing someone get seriously injured or killed
•Experiencing tremendous shock as a result of a traumatic event that happened to a close relative, friend, or significant other
What This All Means
The experience of psychotic symptoms may tell the story of just how  severe a person's case of PTSD is and how well he or she is coping with  the condition. It may also raise red flags about the likelihood of  potentially dangerous behaviors.
Current Psychiatry Reports, Volume 5, Number 3 - SpringerLink
Traumatic brain injury (TBI) can result in serious and disabling  neuropsychiatric disorders, such as cognitive deficits and personality  change, as well as severe and chronic psychosis. This review focuses on  the relationship between TBI and schizophrenia-like psychosis (SLP)  including its epidemiology, diagnostic criteria, clinical presentation,  psychopathology, risk factors, and pathophysiology. The relationships  between post-traumatic epilepsy and SLP, and brain trauma and  schizophrenia, are also discussed. The risk of SLP does increase after  TBI. The clinical presentation has considerable overlap with primary  schizophrenic disorder, with a prominence of persecutory and other  delusions and auditory hallucinations, as well as a lack of negative  symptoms. The onset is often gradual, with a subacute or chronic course.  More severe and diffuse brain injury, especially of the temporal and  frontal lobes, is the most prominent risk factor. Genetic load may also  play a role, but presence of epilepsy could be a protective factor.  Further large and systematic longitudinal studies are needed.