['To determine the effect of subcortical white and gray matter lesions on ECT outcome.', '41 geriatric psychiatric inpatients underwent an MRI scan during their ECT work-up. Periventricular, deep white matter, and subcortical gray matter hyperintensities were graded. The associations of low versus high hyperintensity ratings and symptom scores, Clinical Global Impression severity (CGS) ratings, Montgomery-Asberg Depression Scale score, and number of treatments were examined using t-tests and repeated measures ANOVA.', 'Patients with more severe subcortical gray hyperintensities (SCG) had significantly less improvement as measured by CGS ratings.'] Does severity of subcortical gray matter hyperintensity predict ECT response in geriatric depression?