Am J Geriatr Psychiatry 11:3, May-June 2003 365 Received December 3, 2001; revised April 10, May 31, 2002; accepted May 31, 2002. From the Department of Psychiatry and Traumatic Brain Injury Clinic, Sunnybrook and Women’s College Health Sciences Centre, University of Toronto, Toronto Ontario, CANADA. Addresscorrespon- dence to Dr. Mark Rapoport, FG37, Sunnybrook and Women’s College Health Sciences Centre, 2075 Bayview Ave., Toronto, ON, M4N 3M5, CANADA. Copyright  2003 American Association for Geriatric Psychiatry Age and Major Depression After Mild Traumatic Brain Injury Mark J. Rapoport, M.D., FRCPC Scott McCullagh, M.D., FRCPC David Streiner, Ph.D., CPsych Anthony Feinstein, MPhil., Ph.D., MRCPsych, FRCPC Objective: The authors investigated the relationship between age and major depression in the acute period following mild traumatic brain injury (TBI). Meth- ods: Patients with mild TBI (N210) were assessed for the presence of major depression with the Struc- tured Clinical Interview for DSM-IV. Results: Older patients (age 60-plus) had lower rates of major de- pression than younger patients. Conclusion: Older patients seem to be relatively resilient to major de- pression shortly after mild TBI. (Am J Geriatr Psychia- try 2003; 11:365–369) T raumatic brain injury (TBI) occurs in a bimodal distribution, most commonly among young pa- tients and elderly patients. Most studies of TBI out- come in elderly patients focus on more severely in- jured participants, who fare worse than younger subjects. However, this may not apply to mild TBI, which is far more common than severe injuries in el- derly patients. Mood symptoms and major depression are com- mon after TBI, even when the injury is considered mild. 1 Despite the significant morbidity associated with mood disorders in elderly patients, there has been little study of the role of age in major depression after TBI, and many studies of major depression after TBI have excluded older subjects. Deb et al. 2 studied psychiatric disorders after TBI of all severities in adults of all ages and found that older age was associated with a decreased risk of psy- chiatric illnesses after injury. In an earlier article, we reported that older subjects showed no differences in psychosocial functioning and distress after mild TBI than younger subjects once we controlled for em- ployment. 3 These studies did not, however, specifi- cally address the risk of major depression across the various age-groups. Although Glenn et al. 4 found that advancing age was associated with depressive symptoms after TBI, that study has a number of lim- itations: small sample size (N41), heterogeneous TBI severity, variable duration of follow-up (range: 4.3 to 260 days), as well as a mood assessment limited to self-report. In summary, the relationship between age and ma- jor depression after mild TBI is unclear, reflecting lim- itations in research methodology, and is therefore the focus of the present study. Given the contradictory results from the studies described above, we chose the null hypothesis that major depression will be no more common in older than in younger subjects in the acute period after mild TBI. This is consistent with our previous finding with regard to age and psycho- social outcome. 3 METHODS Patient Selection A consecutive sample of patients attending a TBI clinic for their first follow-up appointment after in- jury was assessed for the presence of major depres- sion. The clinic is part of a large general hospital that serves as a tertiary referral center for trauma patients and is a multidisciplinary program run jointly by psy- chiatry and rehabilitation medicine that also incor- porates occupational therapy and physiotherapy. Pa- tients are referred to the clinic from the emergency department and trauma wards, as well as from com- munity hospitals for rehabilitation after TBI. All participants sustained a non-penetrating mild TBI,