From theoretical and clinical perspectives, it is important to know if selected serotonin-reuptake inhibitors (SSRIs), often administered concurrently with electroconvulsive therapy (ECT), modify seizure duration. In a study with a double-blind, cross-over design, the authors evaluated the effect of citalopram, the most selective SSRI available, on the length of electrically induced seizures and on hormone secretion during ECT. Ten depressed women were given either 20 mg citalopram or placebo orally 2 hours before the third and fourth ECT sessions. Seizure duration was assessed by the cuff technique and from electroencephalographic recordings, whereas blood for prolactin, thyrotropin, and cortisol assessment was sampled before ECT and 5, 10, 20, 30, 40, and 60 minutes after ECT. No adverse effects after the administration of citalopram were recorded. The length of seizures was not statistically different in the citalopram (29.3+/-8.4 seconds) and placebo sessions (28.2+/-9.4 seconds). Neither pre-ECT plasma hormone levels measured 2 hours after citalopram or placebo administration nor the patterns of ECT-induced hormone secretions differed between the two drug and placebo conditions. The lack of effect of citalopram on hormones in this study may be a result of possible deficiencies of the monoaminergic (i.e., serotoninergic) systems in depression. Although safety and efficacy issues were not fully addressed by coadministering citalopram for the long term and throughout the course of ECT, these findings support the view that challenges the typical clinical practice of discontinuing SSRIs before ECT.