The carers of persons with cognitive impairments, including Alzheimer's have migrated to online platforms to seek help, yet studies on the use of online social support within the context of caregiving are underdeveloped. Guided by the social support theory, we examined the association of online and offline social support with depression and anxiety in the United States. Using a subsample from the 2017 and 2018 Health Information National Trends Survey (n = 264), we conducted ordered logistic regression to test mediation and moderation effects, which revealed that only offline, not online social support had a direct association with carers' mental health. In the moderation model, online social support interacted with life stressors, while offline social support interacted with caregiving burden. Findings are supported using a hybrid model that combines online and offline social support to improve carers' mental health.
Keywords: Alzheimer’s carergiving; cognitive impairment; mental health; online; social support.