Increase in plasma proinflammatory cytokines after electroconvulsive therapy in patients with depressive disorder

Electroconvulsive therapy (ECT) is regarded as an effective treatment of drug-resistant depression, but its mechanism of action is mostly unknown. We have previously reported that epileptic seizures result in cerebral production of cytokines, which are also reflected in the plasma. In this study, we tested whether ECT is associated with similar acute release of cytokines.

The plasma levels of cytokines interleukin (IL) 1beta, IL-1 receptor antagonist, and IL-6 were measured using enzyme-linked immunosorbent assay at several time points after ECT. The study included 9 patients who met the diagnostic criteria of major depression (mean age, 55 years; mean Montgomery-Asberg Depression Rating Scale score, 30).

Our results demonstrate that cytokines IL-1beta and IL-6 are increased at 3- and 6-hour time points after ECT. IL-6 release also correlated to the stimulus dose used, suggesting neuronal depolarization as a mechanism of cytokine release.

These results indicate that ECT is associated with rapid induction of inflammatory cytokines most likely in the central nervous system, which are also measurable in the peripheral blood.