Background: To date, there has been a dearth of scientifically tested, established intervention concepts focussed on supporting informal caregivers and embedded in routine health care structures. The aim of this study was to assess effects of a brief telephone intervention for caregivers of persons with cognitive impairment (PCIs) on caregivers' depressiveness and subjective burden.; Methods: A two-arm cluster-randomised controlled intervention study was carried out at 32 German day-care centres.