Theories on Mechanism of Action of Electroconvulsive Therapy

Electroconvulsive therapy (ECT) is a useful yet controversial mode of treatment. Despite being in use for over 70 years, its mechanism of action (MOA) is still not clearly understood. Various theories on MOA of ECT have been proposed over the years. These have included looking at psychological, neurophysiological, neurochemical, neuroendocrine, and neuropeptides mechanisms.An attempt is made here to review the existing literature on the MOA of ECT in a historical perspective. Various theories are discussed in context of the available pre-clinical and clinical research evidence with highlighting of the methodological issues and looking at the relevance of each theory.In summary, there is no single theory that satisfactorily explains the MOA of ECT in various psychiatric illnesses. The need for properly designed, ethically sound pre-clinical and clinical studies is highlighted (German J Psychiatry 2005; 8: 70-84).