MST vs ECT: Which strategy is safer, more effective for bipolar depression?

Magnetic seizure therapy (MST) and electroconvulsive therapy (ECT) deliver similar effects on clinical outcomes in individuals with bipolar depression, reveals a study. However, MST is associated with fewer cognitive adverse effects.

“Despite the established clinical effectiveness of ECT in the treatment of bipolar depression, its acceptance is limited by concerns over cognitive adverse effects,” the authors said.

Participants with bipolar depression were randomized to receive either right unilateral ultrabrief-pulse ECT or MST until they achieved remission, dropped out, or received a maximum of 21 treatments.

The primary outcomes were clinical remission (assessed with the 24-item Hamilton Rating Scale for Depression) and cognitive adverse effects (assessed using the Autobiographical Memory Test [AMT]).

Fifty-five patients met the eligibility criteria, of whom 45 received an adequate trial of treatment. Among those with adequate treatment, six out of 20 (30 percent) patients in the ECT group and five out of 25 (20 percent) in the MST group achieved remission.

Fewer individuals in the MST group (2/28, 7.1 percent) than the ECT group (6/27, 22.2 percent) experienced clinically important worsening in autobiographical memory, defined as a decline of at least 25 percent in AMT score. Secondary clinical outcomes were comparable between treatment groups.

“MST appeared to have resulted in less worsening of autobiographical memory and was better tolerated, suggesting that it may be a safe clinical application to treat bipolar depression,” the authors said. “Given the relatively small sample size of this pilot study, these findings should be considered preliminary.”