Related Experiment Video
Updated: Apr 19, 2026
Pupillary Response as Assessment of Effective Seizure Induction by Electroconvulsive Therapy
Published on: April 11, 2019
A randomized controlled trial of brief and ultrabrief pulse right unilateral electroconvulsive therapy
Colleen K Loo1, Natalie Katalinic2, Deirdre J Smith2
1School of Psychiatry, University of New South Wales, Sydney, Australia (Drs Loo and Martin, Ms Katalinic, and Mr Hadzi-Pavlovic); St George Hospital and Wesley Hospital, Sydney, Australia (Dr Loo and Dr Simpson); Black Dog Institute, Sydney, Australia (Drs Loo and Martin, Ms Katalinic, and Mr Hadzi-Pavlovic); and Dr Simpson Department of Psychiatry, University of Melbourne, and The Melbourne Clinic, Melbourne, Australia (Ms Smith and Addison, Mr Dowling, and Dr Schweitzer); Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, Australia (Dr Ingram). colleen.loo@unsw.edu.au.
Background:
Some studies suggest better overall outcomes when right unilateral electroconvulsive therapy (RUL ECT) is given with an ultrabrief, rather than brief, pulse width.
Methods:
The aim of the study was to test if ultrabrief-pulse RUL ECT results in less cognitive side effects than brief- pulse RUL ECT, when given at doses which achieve comparable efficacy. One hundred and two participants were assigned to receive ultrabrief (at 8 times seizure threshold) or brief (at 5 times seizure threshold) pulse RUL ECT in a double-blind, randomized controlled trial. Blinded raters assessed mood and cognitive functioning over the ECT course.
Results:
Efficacy outcomes were not found to be significantly different. The ultrabrief group showed less cognitive impairment immediately after a single session of ECT, and over the treatment course (autobiographical memory, orientation).
Conclusions:
In summary, when ultrabrief RUL ECT was given at a higher dosage than brief RUL ECT (8 versus 5 times seizure threshold), efficacy was comparable while cognitive impairment was less.
