Relative ineffectiveness of ultrabrief right unilateral versus bilateral electroconvulsive therapy in depression

Bilateral (BL) electrode placement delivered at 2.5 times the initial seizure threshold (ST; 2.5 x ST) is the gold standard method for seizure delivery during electroconvulsive therapy (ECT). However, there is a growing interest in using a high dose (6 x ST) with ultrabrief right unilateral (UB-RUL) electrode placement to reduce the incidence of possible short-term memory problems associated with BL ECT. Although studies have found UB-RUL ECT to have similar effectiveness to BL ECT, the objective of this study was to determine potential differences in efficiency (ie, the number of treatments needed to reach remission).

Electroconvulsive therapeutic data for 56 patients with depression treated during 2006 and 2007 were analyzed via retrospective chart review. A total of 26 patients were started on UB-RUL ECT, whereas 30 patients were started on brief pulse BL ECT.

The patients started on high-dose UB-RUL ECT required significantly more treatments than the patients started on BL ECT (9.4 [3.3] vs 7.7 [2.8] treatments). Of the 26 patients started on UB-RUL ECT, 12 (46%) experienced a lack of effectiveness and/or insufficient seizure induction and were thus switched to BL ECT; the 8 patients switched because of lack of effectiveness received a mean (SD) of 12.2 (2.9) treatments, whereas the 4 patients switched because of insufficient seizure induction received a mean (SD) of 11.3 (3.6) treatments.

These findings add to an emerging story of reduced efficiency of UB-RUL versus BL electrode placement for an index course of ECT for the treatment of depression.