This study aims to investigate the clinical effects of benzodiazepines or anticonvulsant use during a course of electroconvulsive therapy (ECT).
A case report study of a patient who received ECT with and without concomitant flurazepam and pregabalin is presented. The literature on the use of benzodiazepines and anticonvulsants during ECT is reviewed.
A woman with treatment resistant depression received a course of ECT while taking flurazepam and pregabalin, but seizures were of short duration and symptomatic improvement was minimal. After discontinuation of flurazepam and pregabalin, a course of right unilateral ultrabrief ECT was associated with adequate seizures and remission of depression and suicidal ideation. Our literature review suggests that benzodiazepines decrease seizure duration, but most evidence shows no association with increased seizure threshold. One prospective RCT and 3 large retrospective studies found that benzodiazepines compromise the efficacy of unilateral but not bilateral ECT. Regarding anticonvulsants, several studies had varied and contradictory results on their effect on seizure duration and seizure threshold. Of the 2 large retrospective studies and 3 RCTs, only 1 retrospective study showed that anticonvulsants decrease the efficacy of ECT.
Judicious assessment of all medications used in combination with ECT is recommended. Overall, published studies suggest that benzodiazepines and anticonvulsants impact the clinical outcomes of ECT less than what would be expected given their pharmacologic effects. However, there are significant gaps in the literature, including a lack of study on suprathreshold stimulation of right unilateral ECT and the possibility of a greater effect with higher medication doses.
From the *Department of Psychiatry, †Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, ‡Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, §Institute of Medical Science, Faculty of Medicine, ∥Women's Inpatient Unit, Centre for Addiction and Mental Health, and ¶Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
Received for publication April 30, 2017; accepted June 16, 2017.
Reprints: Zafiris J. Daskalakis, MD, PhD, FRCPC, Centre for Addiction and Mental Health, 1001 Queen St W, Unit 4-1, Toronto, Ontario, M6J1H4, Canada (e-mail: Jeff.Daskalakis@camh.ca).
D.M.B. receives research support from the Canadian Institutes of Health Research (CIHR), Brain Canada, Weston Brain Institute, National Institutes of Health (NIH), Temerty Family through the Centre for Addiction and Mental Health (CAMH) Foundation, and the Campbell Family Research Institute. He received nonsalary operating funds and in-kind equipment support from Brainsway Ltd for an investigator-initiated study. He is the site-principal investigator for 3 sponsor-initiated clinical trials from Brainsway Ltd. He received in-kind equipment support from Tonika/Magventure for an investigator-initiated study. He received medication supplies from Indivior for an investigator-initiated trial. In the last 5 years, B.H.M. has received research support from Brain Canada, the CAMH Foundation, the CIHR, the NIH, Bristol-Myers Squibb (medications for an NIH-funded clinical trial), Eli Lilly (medications for an NIH-funded clinical trial), and Pfizer (medications for an NIH-funded clinical trial). In the last 3 years, Z.J.D. has received research and equipment in-kind support for an investigator-initiated study through Brainsway Inc and Magventure Inc. Z.J.D. has also received monies for participation on an advisory board from Sunovion Inc. Finally, Z.J.D. owns more than US $10,000 (CAD) in stock of Biogen Inc. This work was supported by the Ontario Mental Health Foundation, the CIHR, the Brain and Behaviour Research Foundation, and the Temerty Family and Grant Family and through the CAMH Foundation and the Campbell Institute. For the remaining authors, none were declared.