Traumatic Brain Injury and Schizophrenia in Members of Schizophrenia and Bipolar Disorder Pedigrees
Journal Title
American Journal of Psychiatry
Keywords
Readers/Advisors
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Term and Year
Publication Date
2001-03
Book Title
Publication Volume
158
Publication Issue
3
Publication Begin
440
Publication End
446
Number of pages
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Journal Issue
Abstract
Objective: Schizophrenia following a
traumatic brain injury could be a phenocopy of genetic schizophrenia or the consequence of a gene-environment interaction.
Alternatively, traumatic brain injury and
schizophrenia could be spuriously associated if those who are predisposed to develop schizophrenia have greater amounts
of trauma for other reasons. The authors
investigated the relationship between traumatic brain injury and psychiatric diagnoses in a large group of subjects from
families with at least two biologically related first-degree relatives with schizophrenia, schizoaffective disorder, or bipolar
disorder.
Method: The Diagnostic Interview for Genetic Studies was used to determine history of traumatic brain injury and diagnosis for 1,275 members of multiplex bipolar
disorder pedigrees and 565 members of
multiplex schizophrenia pedigrees.
Results: Rates of traumatic brain injury
were significantly higher for those with a
diagnosis of schizophrenia, bipolar disorder, and depression than for those with
no mental illness. However, multivariate
analysis of within-pedigree data showed
that mental illness was related to traumatic brain injury only in the schizophrenia pedigrees. Independent of diagnoses,
family members of those with schizophrenia were more likely to have had
traumatic brain injury than were members of the bipolar disorder pedigrees.
The members of the schizophrenia pedigrees also failed to show the gender difference for traumatic brain injury (more
common in men than in women) that
was expected and was present in the bipolar disorder pedigrees. Subjects with a
schizophrenia diagnosis who were members of the bipolar disorder pedigrees
(and thus had less genetic vulnerability to
schizophrenia) were less likely to have
had traumatic brain injury (4.5%) than
were subjects with schizophrenia who
were members of the schizophrenia pedigrees (and who had greater genetic vulnerability to schizophrenia) (19.6%).
Conclusions: Members of the schizophrenia pedigrees, even those without a
schizophrenia diagnosis, had greater exposure to traumatic brain injury compared to
members of the bipolar disorder pedigrees. Within the schizophrenia pedigrees,
traumatic brain injury was associated with
a greater risk of schizophrenia, consistent
with synergistic effects between genetic
vulnerability for schizophrenia and traumatic brain injury. Posttraumatic-braininjury schizophrenia in multiplex schizophrenia pedigrees does not appear to be a
phenocopy of the genetic disorder.