The use of electroconvulsive therapy (ECT) in the clinical practice in patients with dementia syndromes continues to cause controversy. In this case, the clinical difficulty existing when making a differential diagnosis between depressive episodes and incipient dementia picture is presented. The interrelation between these two pictures and the possible common etiological origin are also evaluated. Electroconvulsive therapy is effective and safe in functional improvement in affective and dementia disorders in elderly patients.