Increased risk of schizophrenia following traumatic brain injury: a 5-year follow-up study in Taiwan.

Background: Whether traumatic brain injury (TBI) is an independent risk factor for the subsequent development of schizophrenia has evoked considerable controversy. No evidence has been previously reported from Asia. This study estimated the risk of schizophrenia during a 5-year period following hospital admission for TBI relative to a comparison group of non-TBI patients during the same period in Taiwan.

Method: Two datasets were linked: the Traumatic Brain Injury Registry and the Taiwan National Health Insurance Research Dataset. A total of 3495 patients hospitalized with a diagnosis of TBI from 2001 to 2002 were included, together with 17 475 non-TBI patients as the comparison group, matched on sex, age, and year of TBI hospitalization. Each individual was followed for 5 years to identify any later diagnosis of schizophrenia. Cox proportional hazard regressions were performed for analysis.

Results: During the 5-year follow-up period, patients who had suffered TBI were independently associated with a 1.99-fold (95% confidence interval 1.28-3.08) increased risk of subsequent schizophrenia, after adjusting for monthly income and residential geographical location. The severity and type of TBI was not associated with the subsequent development of schizophrenia.

Conclusions: Our findings add important evidence from Asia and suggest a potential link between TBI and schizophrenia. Our study suggests that clinicians and family members should be alert to possible neuropsychiatric conditions following TBI.