Washington: People who have suffered from a traumatic brain injury are at an increased risk of developing schizophrenia, a new study has claimed.
Previous studies on traumatic brain injury, or TBI, and schizophrenia have yielded mixed results as to whether the conditions are linked.
But the new study, published in the journal Schizophrenia Bulletin, found that people with TBI are 1.6 times more likely to develop schizophrenia and the risk was particularly high in those with a family history of the psychiatric condition, LiveScience reported.
While the new findings suggest the link does exist, they don`t prove that brain injuries cause schizophrenia. And it could be that patients were already developing the psychiatric condition when their injury occurred, the researchers said.
More work needs to be done to find exactly what`s behind this relationship, they said.
TBI results from a jolt or blow to the head, or an injury that penetrates the skull. It is known to increase the risk of some psychiatric disorders, including anxiety disorders,
substance use disorders and personality change.
For their research, Mary Cannon, of the Royal College of Surgeons in Dublin, and colleagues analysed nine past studies that included participants with and without a TBI.
Overall, the researchers found that TBI was associated with an increased risk of schizophrenia. People who suffered TBI and also had a relative with schizophrenia were 2.8 times more likely to develop the psychiatric condition than those who hadn`t had TBI, they said.
According to the WHO, schizophrenia affects about seven out of every 1,000 adults worldwide.
The study also found that the risk of schizophrenia did not increase in more severe brain injuries. That may mean other factors, such as the location of the trauma, matter more
in terms of schizophrenia risk, the researcher said.
The researchers didn`t conduct any new trials themselves, so their study is only as good as the data they chose to review, said Dr Dolores Malaspina, a professor of psychiatry
and environmental medicine at New York University.
However, the studies included in the new analysis are "excellent", Malaspina said.
She said that brain injury can pull on and break neural connections, which can have real, biological consequences.
Depression and personality changes are common repercussions of TBI. There are some cases in which a patient has developed schizophrenia due in part to their TBI. And some
people may have genes that predispose them to schizophrenia once they experience an environmental "trigger", such as TBI, Malaspina said.
"Exposure to a brain injury in those people can unmask a psychotic illness," or bring one forward that would have otherwise been compensated, she said.
On the other hand, she said, having schizophrenia in its early stages may increase your risk of experiencing TBI. These patients could experience lapses in judgement and attention that may make them prone to accidents, she added.