The Cornell Scale for Depression in Dementia is introduced. This is a 19-item clinician-administered instrument that uses information from interviews with both the patient and a nursing staff member, a method suitable for demented patients. The scale has high interrater reliability (kw = 0.67), internal consistency (coefficient alpha: 0.84), and sensitivity. Total Cornell Scale scores correlate (0.83) with depressive subtypes of various intensity classified according to Research Diagnostic Criteria.