The study of discrete organic cerebral lesions resulting in clearly definable psychiatric disorders may provide an understanding of the underlying patho-physiological basis of these disorders. However, the relation between lesion location and psychiatric illness after stroke remains unclear. Fifty five patients referred to hospital were identified who had a single lesion on CT which was consistent with their neurological presentation and who did not have evidence of a persistent affective disorder at the time of the stroke. Six months after stroke standardised psychiatric assessment disclosed that 26% of the patients met DSM-IV criteria for an anxiety or depressive disorder, with depression the most common diagnosis (20%). Pathological emotionalism was diagnosed in 18% of patients, particularly those who were depressed (p<0.0001). Depression was significantly associated with larger lesions involving the right cerebral hemisphere (p=0.01). The importance of depression as a consequence of stroke has been clarified by the studies in this area. However, wide confidence intervals support the possibility that significant results may be due to chance. A systematic review of these studies is now needed if a consensus is to be reached.