The main mechanism of action in electroconvulsive therapy (ECT) is the induction of a generalized clonic seizure. This seizure is triggered by the delivery of an electric current to the patient’s brain using electrodes placed on the patient’s head.
The nervous system is regulated by electrical currents and disrupting those currents by way of an induced seizure has demonstrated beneficial effects in patients with severe depression and schizophrenia.
Exactly how the induced convulsion achieves this is not clear and many animal models have been studied to try and elucidate the underlying mechanism of the therapy’s effects. However, despite the various similarities between human and animal brains, many dispute the translational value of these studies in terms of understanding depression in humans.
Some of the theories derived from animal research regarding the mechanism of ECT include:
- Murine studies have shown that on application of ECT, there is a rise in the level of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) in the hippocampus region of the brain. Evidence shows that rises in blood levels of BDNF and VEGF can increase hippocampal neurogenesis.
- Studies have also shown that ECT can increase the BDNF level in people who do not respond to antidepressant drugs.
Reviewed by Sally Robertson, BSc