Although the safety and efficacy of electroconvulsive therapy (ECT) is acknowledged by most, concern has repeatedly been expressed that the treatment may have some lasting effects on the brain. To study potential morphological changes, 22 patients with a history of ECT were submitted to a detailed clinical evaluation and a brain CT scan examination. Age- and sex-matched control subjects comprised a group of comparable patients, none of whom had received ECT, and a second control group of healthy volunteers. Patients had larger ventricle/brain ratios and cortical "atrophy" scores than normal controls, but no association was found between these radiological measures and a previous history of ECT. Hence, the present data are consistent with recent reports that affective disorders may be associated with enlarged brain ventricles, although the clinical significance of such findings remains unclear. In line with previous investigations age correlated significantly with cortical "atrophy" scores and ventricle/brain ratios for all subjects. Statistical tests of correlations between duration of illness, previous psychotropic drug exposure and CT scan appearances were mainly inconclusive.