The burden of affective disorders includes costs and the pain and suffering of affected individuls. Burden can be perceived from social and private perspectives. Although no ideal measure of burden exists, ample evidence documents the extensive cost and other negative impacts of affective disorders. Affective disorders are associated with disruptive family relations, higher health care costs for comorbid conditions, elevated rates of suicide, and lower productivity. Reserch should focus on improving measures of burden in general and on quantifying burden from the standpoint of diverse population groups.