Electroconvulsive Therapy Pulse Amplitude and Clinical Outcomes

Christopher C. Abbott, Davin Quinn, Jeremy Miller, Enstin Ye, Sulaiman Iqbal, Megan Lloyd, Thomas R. Jones, Joel Upston, Zhi De Deng, Erik Erhardt, Shawn M. McClintock

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


Introduction: Electroconvulsive therapy (ECT) pulse amplitude, which determines the induced electric field magnitude in the brain, is currently set at 800–900 milliamperes (mA) on modern ECT devices without any clinical or scientific rationale. The present study assessed differences in depression and cognitive outcomes for three different pulse amplitudes during an acute ECT series. We hypothesized that the lower amplitudes would maintain the antidepressant efficacy of the standard treatment and reduce the risk of neurocognitive impairment. Methods: This double-blind investigation randomized subjects to three treatment arms: 600, 700, and 800 mA (active comparator). Clinical, cognitive, and imaging assessments were conducted pre-, mid- and post-ECT. Subjects had a diagnosis of major depressive disorder, age range between 50 and 80 years, and met clinical indication for ECT. Results: The 700 and 800 mA arms had improvement in depression outcomes relative to the 600 mA arm. The amplitude groups showed no differences in the primary cognitive outcome variable, the Hopkins Verbal Learning Test-Revised (HVLT-R) retention raw score. However, secondary cognitive outcomes such as the Delis Kaplan Executive Function System Letter and Category Fluency measures demonstrated cognitive impairment in the 800 mA arm. Discussion: The results demonstrated a dissociation of depression (higher amplitudes better) and cognitive (lower amplitudes better) related outcomes. Future work is warranted to elucidate the relationship between amplitude, electric field, neuroplasticity, and clinical outcomes.

Original languageEnglish (US)
Pages (from-to)166-178
Number of pages13
JournalAmerican Journal of Geriatric Psychiatry
Issue number2
StatePublished - Feb 2021


  • Electroconvulsive therapy
  • cognition
  • depression
  • pulse amplitude

ASJC Scopus subject areas

  • Geriatrics and Gerontology
  • Psychiatry and Mental health


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