Background: The association between epilepsy and depressive illness has long been established. However, though various explanations-psychosocial and anatomical-have been proposed findings from studies are inconsistent and often contradictory. Aims: This study aimed to compare the features of those people with epilepsy seen in a secondary care setting who developed a depressive illness with those that did not. Method: Information regarding the patient's epilepsy, history and presence of depressive illness and perceived social functioning was gathered from case notes, questionnaire and patient interview. Results: The experience of a depressive episode was associated with the presence of a right-sided lesion, attacks occurring more than once each month, diagnosis made in adulthood and a perceived marked effect of the epilepsy on mobility and social activity. Conclusion: These findings are not all consistent with work already carried out in this field. However, they do point to a multifactorial aetiology of depressive illness in this group as is the case in the general population. Possible explanations for frequently contradictory findings are discussed. (C) 2002 Published by Elsevier Science Ltd on behalf of BEA Trading Ltd.