The Substance Abuse and Mental Health Services Administration (SAMHSA) and Administration on Aging (AoA) commissioned a series of Issue Briefs to address behavioral health issues that are important to older Americans. The Issue Briefs identify key information and opportunities for action that can improve the lives of older people. This Issue Brief explores the behavioral health needs of informal caregivers, defined as any relative, partner, friend or neighbor who has a significant personal relationship with, and provides a broad range of assistance for, an older person or an adult with a chronic or disabling condition including both medical and behavioral health conditions. This Issue Brief will: (1) Describe the characteristics of caregivers including an estimate of the numbers of caregivers in the United States and explain who they are, what they do, and the impact that caregiving has on their health and well-being, such as an increased risk for mental illness and substance misuse; (2) Describe special issues related to caregivers of people with behavioral health conditions; (3) Highlight evidence-based interventions to decrease common caregiver problems, such as depression, anxiety, and anger, and to improve coping and problem-solving skills; (4) Suggest key actions that aging network and behavioral health providers can take to address the behavioral health needs of caregivers; and (5) Provide information about caregiving resources, including the National Family Caregiver Support Program (NFCSP).