In this article the authors describe two different ways in which the relationship between affective disorders and cerebrovascular disease can be studied. First, the occurrence of so called 'post stroke depression' offers an opportunity to study this relationship. Second, neuroradiological investigations in patients with a major depressive disorder can be performed. The authors review the literature on both subjects. Until now, unequivocal conclusions concerning vascular lesions on CT or MRI and depressive features in the elderly cannot be drawn from research data available. Moreover, the so-called Post-stroke depression is still not fully understood. Some difficulties encountered in this area of research are also addressed. The authors suggest a neurological cause for the late onset types of major depressive illness and also suggest that these depressions are phenomenologically different from the early onset subtypes of depressive illness. The post stroke depression also seems to differ phenomenologically from major depression according to DSM-criteria.