Depression in the First Year after Traumatic Brain Injury

The aims of this study were to document the frequency of major and minor depressive episodes in the first year after traumatic brain injury (TBI), taking into account TBI severity and pre-morbid history of major depression, and to describe trajectories of depressive episodes. Participants were 227 adults who were hospitalized post-TBI (76% male; mean age=41 years; 50% mild, 33% moderate, and 17% severe TBI). Major and minor depressive episodes were assessed with the Mini International Neuropsychiatric Interview at three time points (4, 8, and 12 months after TBI). Overall, 29% of participants had a major depressive episode in at least one of the three assessments, with fairly stable rates across assessments. Participants with mild TBI were more likely than those with moderate/severe TBI to be diagnosed with major depression, as were individuals with a positive pre-morbid history of depression compared to those without such history. In addition, 13% of participants had a minor depressive episode in at least one of the three assessments. Rates of minor depression significantly decreased from 4 to 8-12 months post-injury. Results also revealed a wide variety of trajectories of depressive episodes across assessments. Of note, 52% of major depression cases still fulfilled diagnostic criteria 4 months later, whereas 38% of minor depression cases deteriorated to major depression at the following assessment. These findings suggest that depression is highly prevalent after TBI, and monitoring of patients with subthreshold depressive symptoms is warranted in order to prevent the development of full-blown major depressive episodes.