Background: Caregiving in depression imposes a complex health and economic burden. Moreover, there is a paucity of studies examining the impact of caregiving for adult relatives with unipolar depression (CG-UD). This study assessed the burden among CG-UD in five western European (EUR5) countries (France, Germany, Italy, Spain and the United Kingdom) compared with caregivers of adults with other chronic comorbidities (CG-OD) and general non-caregiving (non-CG) population.