Memantine for late‐life depression and apathy after a disabling medical event: a 12‐week, double‐blind placebo‐controlled pilot study

Abstract

Preclinical data suggests that memantine, a noncompetitive glutamate N-methyl- D-aspartate-receptor blocker used for the treatment of moderate to severe Alzheimer's disease, could reduce depressive and amotivated behavior occurring in the context of psychosocial stress. Therefore, we examined whether memantine could reduce depressive symptoms and amotivation manifesting in older adults after a disabling medical event, thereby improving their functional recovery. We recruited subjects aged 60 years and older who had recently suffered a disabling medical event and were admitted to a skilled nursing facility for rehabilitation. Participants with significant depressive symptoms, defined as a Hamilton Rating Scale for Depression score of 10 or greater, and/or significant apathy symptoms, defined as an Apathy Evaluation Scale score of 40 or greater, were randomized to memantine (10 mg/d for 1 week, then 10 mg twice daily) or placebo, for 12 weeks. We also recruited participants without depressive or apathy symptoms for naturalistic follow-up as a non-depressed comparison group. Depressive and apathy symptoms were main outcomes; functional recovery, and self-report rating of helplessness, and onset of new depressive disorders were secondary outcomes. Thirty-five older adults with significant depressive and/or apathy symptoms were randomized, of whom 27 (77.1%) completed the 12 week randomized controlled trial. Both groups showed reduction in depressive symptoms (but no significant reduction in apathy symptoms) and improved function. However, there were no group differences between the memantine-randomized and placebo randomized participants on any outcome. Memantine was not associated with superior affective or functional outcome compared with placebo in medically rehabilitating older adults with depressive and apathy symptoms.