Effects of Psychotropic Drugs on Seizure Threshold during Electroconvulsive Therapy

Abstract

Objectives To analyze the relationship between seizure threshold (ST) and psychotropic drugs in patients treated with ECT. Methods We examined clinical data from 43 patients. ST was titrated at each treatment session. We examined associations between ST and psychotropic drugs using multivariate correlation analyses. Data are presented as initial ST, the difference in ST between the first and 10th sessions (Delta ST10th), and the mean difference in ST between the first and last sessions (mean Delta STlast). Results Multivariate regression analyses showed associations between initial ST and the total chlorpromazine-equivalent dose of anti psychotics (beta=0.363, p<0.05). The total fluoxetine-equivalent dose of antidepressants was associated with Delta ST10th (beta=0.486, p<0.01) and mean Delta STlast (beta=0.472, p<0.01). Conclusion Our study elucidated possible effects of psychotropic drugs on ST shifts. Larger doses of antipsychotics were associated with higher initial ST, whereas higher doses of antidepressants were associated with stronger shifts in ST.