A range of both care recipients' and caregivers' characteristics have been associated with caregiver sleep quality measured subjectively and objectively. Care recipient factors associated with caregiver sleep quality include fall risk and sleep quality, while caregiver factors include stress, duration, intensity, provision of medical/nursing care tasks, and even particular serotonin genotypes (e.g. short allele carriers for 5-HTTLPR). While the greatest focus has been on dementia caregivers, recent work suggests groups such as end-of-life caregivers, former caregivers, and caregivers with multiple care roles (e.g. child, older adult, paid care) have sleep disturbances that vary by their unique contexts. Caregiver's sleep, particularly subjective assessments, relates to their mood and physiological well-being; and evidence suggests that sleep may be an important mediator linking care stressors with mental health. Factors such as mindfulness and sense of coherence may protect caregivers from sleep disturbances.