Electroconvulsive therapy (ECT), formerly known as electroshock therapy, is a psychiatric treatment in which seizures are electrically induced in patients to provide relief from severe mental disorders - especially major depressive disorders, catatonia, etc.
The therapy has been in use since 1938, and although it provides long term relief (typically months) in about half of patients treated, the side effects (memory loss, cognitive impairment) can be very severe - and in some cases permanent.
The mechanism of its action is as yet undetermined.
“Despite decades of research, the exact mechanism of action of ECT remains elusive. Neuroimaging studies in people who have had ECT, investigating differences between responders and nonresponders, and people who relapse, find that responders have anticonvulsant effects mostly in the frontal lobes, which corresponds to immediate responses, and neurotrophic effects primarily in the medial temporal lobe.”