Electroconvulsive Therapy Increases Plasma Levels of In t erleukin-6"

There is now ample evidence of close interactions between the central nervous system and the immune system. Neurohormones and neurotransmitters play an important role in immunomodulation. Similarly, products of the immune system contribute to neuroendocrine secretion and may also possess specific behavioral properties. Animal studies have shown that stress can interfere with immune regulation and mediate the release of interleukins. Human studies assessing interactions between stress and immunity have been relatively scarce. We have reported earlier that patients suffering from a major depression show a decrease in natural killer (NK) cell activity. ' We have also shown that electroconvulsive therapy (ECT), an effective and well known treatment for depression, increases NK cytotox-icity.2 We therefore formulated the hypothesis that ECT will also be accompanied by an increase in plasma levels of interleukin-6 (IL-6). Eight hospitalized psychiatric patients who were suffering from affective disor-ders and who were referred to the ECT service by their attending physicians were included in the study. Their mean age was 48.9 yr (range = 17 to 82 yr). Four patient