Reliability of a standardized brief-pulse stimulus in ECT

The reliability of a standardized brief-pulse stimulus in eliciting a satisfactory convulsive response was evaluated under normal clinical conditions. A total of 89 patients were given 961 initial treatments. Of these, 757 were at the standardized level with a success rate of 89%. A total of 204 trials were given at higher-than-standardized levels. Treating these as standardized level failures, the overall success rate was 70%. The probability that a standardized stimulus given to any patient at any point in the treatment series would be successful was about 7 chances in 10. Implications for the selection of ECT stimuli were discussed.