Objectives: To quantitatively review the literature comparing depressed mood, anxiety and psychological distress in caregivers (CGs) of older adults with Alzheimer's disease (AD) with non-caregivers (NCGs) Methods: Eighteen independent studies comparing AD CGs (N = 2378) with NCGs (N = 70,035) were evaluated in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines.