Bipolar disorder is associated with a higher risk for traumatic brain injury (TBI), according to the findings of a longitudinal cohort study published in Psychiatry Research.
Researchers used the Longitudinal Health Insurance Database of Taiwan to access patient information dating from 1998 to 2010. Patients in the bipolar group had a history of at least 1 psychiatric inpatient stay for bipolar disorder. Patients in the control group (n=9044) were randomly selected and matched with patients in the bipolar group (n=1017) at a ratio of 9:1 based on age, sex, and year of cohort entry. The annual incidence rate of TBI was calculated as the number of new cases from 1998 to 2010 divided by the total number of person-years available in the records.
The incidence of subsequent TBI was significantly higher in patients with bipolar disorder than in the control group. Over the course of the study, 5.9% of patients in the bipolar group and 3.2% of patients in the control group experienced TBI (P <.0001). The risk for TBI for those with bipolar disorder was highest in the first 2 years following inpatient treatment. Age and medication use were found to be modifying factors, with a higher risk in middle-aged patients and in patients using psychotropic medication used to treat bipolar disorder, including antipsychotics, benzodiazepines, antidepressants, and mood stabilizers. Patients with a history of recurrent hospitalization also had an increased risk for TBI compared with those without recurrent hospitalization.
The researchers noted that restricting the bipolar study group to only those with a history of inpatient visits compromised study sensitivity, and that findings should be extrapolated with care. Still, these data indicate that specific strategies should be developed to prevent TBI in patients with bipolar disorder.
Huang M-F, Su C-H, Tu H-P, et al. Association between bipolar disorder and subsequent traumatic brain injury in patients who received inpatient treatment. Psychiatry Res. 2018;261:517-521.