The relevance of a clinical diagnosis of depression for explaining the discrepant relationships of hopelessness and depression with suicidal ideation was studied. The Beck Depression Inventory (BDI), Hopelessness Scale (BHS), and the Scale for Suicide Ideation (SSI) were administered to 1,306 (72.8%) patients with at least one DSM‐III‐R mood disorder and 488 (27.3%) patients without any mood disorders. A multiple regression analysis was conducted, and hopelessness was 1.3 times more important than depression was for explaining suicidal ideation. The interactions of the BDI and BHS with diagnostic group were not significant.