Meta-analysis of initial seizure thresholds in electroconvulsive therapy

Area of Science:

• Neuroscience
• Psychiatry
• Clinical Pharmacology

Background:

• Electroconvulsive therapy (ECT) electrical dosage relies on fixed-dose, age-based, or titration methods.
• Estimating the initial seizure threshold (IST) is considered essential for suprathreshold dosing in ECT.

Purpose of the Study:

• To systematically review common IST levels in ECT.
• To define cut-off values for high IST.
• To summarize factors associated with IST.

Main Methods:

• Systematic literature search of Medline and PsycINFO (1966-2008).
• Inclusion of 46 studies (3,023 patients) reporting IST levels or associated factors.
• Meta-analysis of 30 unilateral (1,326 patients) and 27 bilateral (1,116 patients) ECT samples.

Main Results:

• Weighted mean IST: 68.2 mC (unilateral ECT) and 111.6 mC (bilateral ECT).
• High IST cut-off values: 121 mC (unilateral) and 221 mC (bilateral).
• Male gender and bilateral electrode placement were associated with increased IST.

Conclusions:

• Calculated suprathreshold doses for unilateral and bilateral ECT align with fixed-dose and age-based strategies.
• IST estimation provides a basis for refined electrical dosing in ECT.
• Findings support the importance of considering IST for personalized ECT.