How ECT works by Natasha Tracy​

How Does Electroconvulsive Therapy (ECT) Work?

In the book I’m writing on electroconvulsive therapy (ECT) I’ve had to address the question as to how ECT works. However, in spite of the fact that ECT has been in use since the 1930s we really don’t know how ECT works.

But recently we may have gotten a bit closer to figuring it out.
Electroconvulsive Therapy (ECT) and Brain Derived Neurotrophic Factor
One of the things we have noted is that people who undergo ECT have measurably increased levels of brain derived neurotrophic factor (BDNF) which is critical in supporting healthy cells and cell growth in the brain. This increase in BDNF is something we’ve noticed when people take antidepressants as well. When you think about it, it makes sense that this would be part of why ECT and other therapies work as it combats the shrinking of the brain seen in depression and other mental illnesses.

Electroconvulsive Therapy (ECT) “Reboots” the Brain
And one of the things I have said is that electroconvulsive therapy does not “reboot” the brain. There is just nothing similar to this analogy that we can point to with regards to ECT. Until now, that is.

Recent research shows that functional connectivity in areas of the brain may be up-regulated in people with depression. In other words, there are areas of the brain with too much connectivity. This theory is known as the “hyperconnectivity hypothesis.”
How Does ECT Work in the Brain

This seems counter intuitive when you think of depression but I suppose it’s like anything else, too much of anything can be a bad thing, especially in the brain.
Recently a study was done where functional magnetic resonance imaging (fMRI) measured the connectivity in areas of the brain. And specifically around the left dorsolateral prefrontal cortical region it was found ECT decreased the functional connectivity, and this decrease in functional connectivity seemed to correlate with positive results from the ECT on depressive symptoms.
Thus ECT was found to change the functional architecture of the brain in a way that helped with depression.
Note that the study size was extremely small but that this is typical for studies using technology like fMRIs. Thus, we cannot say this study proves anything but we can say it leads us in a new, and perhaps promising, direction in terms of discovering how ECT works.
Please see Electroconvulsive therapy reduces frontal cortical connectivity in severe depressive disorder for all the details.
Why Does it Matter How ECT Works?
Well, on the one hand, it doesn’t. For the people for whom ECT has worked, how it worked doesn’t matter a lick. However, the end goal for researchers is to figure out how ECT works so that they can retain the therapeutic component of the treatment while reducing the side effects (like memory loss). Maybe this study got us one step closer.