An investigation of the relationship between depressive psychosis and subnutrition in the elderly patient is described. The difficulties of assessing the nutritional state and depressive symptoms in elderly patients are discussed. A statistically significant relationship (p = < 0.05) between depressive psychosis and subnutrition without adequate physical cause is demonstrated. Many of these depressive illnesses are evidently undiagnosed and consideration is given to ways of increasing accuracy in the diagnosis of depressive psychoses in the elderly. The availability of thymoleptic drugs allows many of these patients to be treated at home or in the Geriatric Unit to which they are admitted. The value of regular psychiatric consultation in geriatric units is stressed.