How Does ECT Work in the Brain?
Electroconvulsive therapy (ECT) is an uncommon treatment for severe, chronic depression. It is used sparingly, partially because our understanding of why and how it works is still in the dark ages. It also doesn’t help that it can cause memory loss in many patients who undergo it (usually confined to just memory around ECT treatments, but occasionally also around older, longer-term memories as well), as well as increasing attention and concentration problems in a minority of people who try ECT.
However, a new study sheds light on the possible mechanism for how electroconvulsive therapy works, based upon one theory of how depression works in the brain.
The theory goes like this — depression isn’t caused by too little brain activity. It’s actually caused by too much brain activity, an overactive brain that has accidentally “hot-wired” multiple brain networks together. (How and why this hot-wiring occurs is still a mystery.)
So how can ECT undo this hot-wiring?
It’s theorized that ECT may undo this hot-wiring, and return the brain’s neural networks to normal functioning:
In a study led by psychiatrist Ian Reid of Aberdeen, Schwarzbauer and colleagues performed functional magnetic resonance imaging (fMRI) scans of nine depressed patients before and after ECT. Rather than focusing on activity in previously suspected brain areas, the researchers examined connectivity in the brain as a whole, examining changes in blood oxygenation in about 27,000 points known as voxels (the 3D imaging equivalent of pixels on a computer screen). […]
After treatment with ECT, connectivity was dramatically decreased in one cluster of voxels around an area called the dorsolateral prefrontal cortex, the researchers report today in the Proceedings of the National Academy of Sciences. Decreases in connectivity reflected improvements in symptoms, as reported by the patients. […]
This finding indicates that ECT reduces the influence of the dorsolateral prefrontal cortex on this nexus.
Granted, this is a tiny study done on just 9 patients, so we really can’t generalize these findings to a broader population at this time until the findings are properly replicated by other researchers.
Still, it’s an interesting preliminary finding that may explain why ECT can be effective. It fails to explain, however, why antidepressants work (assuming, logically, that most depression functions through similar brain mechanisms).
Read the full article: Insight Into a Shocking Therapy for Depression
Grohol, J. (2012). How Does ECT Work in the Brain?. Psych Central. Retrieved on October 6, 2015, from http://psychcentral.com/blog/archives/2012/03/20/how-does-ect-work-in-the-brain/