The things that this experiment examined associations between caregiving intensity and mental health among cancer caregivers at the population level and potential moderation by an actionable intervention target, support service needs. Behavioral Risk Factors Surveillance System survey data (2015) from caregivers of adult patients with cancer was analyzed. Caregiving intensity included hours per week caregiving (high, > 20; low, ≤ 20) and caregiving duration (long, > 2 years; short, ≤ 2 years). Mental health was reported as the number of mentally unhealthy days (MUDs) in the past 30. 

A total of 1,831 caregivers were included in the study, representing approximately 1.1 million cancer caregivers in the 18 US states, distributed with the following intensity: 122 (8.3%) caregivers reported care at high hours/long duration, 213 (13.1%) high hours/short duration, 329 (18.4%) low hours/long duration, and 910 (60.2%) low hours/short duration. Mean MUDs was 6 (SE, 0.5). The highest reported unmet service need was help with service access (48.4%). Higher caregiving intensity and support service need were associated with more MUDs (P < .05), with a significant interaction (P = .02) between caregiving intensity and unmet support service needs. 

High-intensity cancer caregiving was associated with poor mental health, especially for those reporting support service needs.