Background: Caregivers of patients with neurodegenerative diseases are at heightened risk for serious health problems, but health differences between individual caregivers abound. Aims: To determine whether atrophy in patient brains could be used to identify caregivers at heightened risk for health problems and which patient variables mediate this relationship. Methods: In 162 patient-caregiver dyads, we assessed patient atrophy using structural MRI, caregiver health, and patient behavior and cognitive symptoms. Results: Patient atrophy in the right insula and medial frontal gyrus was associated with worse caregiver health; this relationship was partially mediated by patient neuropsychiatric symptoms, and assessing atrophy in these regions improved predictions of poor caregiver health above and beyond patient behavioral symptoms. Conclusions: This study shows the value of patients’ brain data in identifying caregivers at risk for becoming sick themselves.