Depression is an independent risk factor for mortality in advanced age and accounts for substantial functional impairment (Reynolds et al. 2008). It may be characterized by more irritability and apathy, with less overt sadness. The changes in role functioning that often occur with aging may be exacerbated by the abrupt loss of functional capacity because of TBI. Greater dependence on others for cognitive and, at times, physical tasks may engender feelings of loss and helplessness. Antidepressant therapy may be effective, though it is important to differentiate between depression and TBI- or dementia-related apathy syndromes to avoid unnecessary exposure to psychoactive medications. Dosing and titration should be adjusted based on the time-honored philosophy of "start low, go slow" in recognition of heightened sensitivity to medication side effects and potential drug-drug interactions with other nonpsychotropic medications.