Scottish scientists have discovered how electric shock therapy (ECT) helps beat severe depression, after investigating how the therapy alters the brain's connectivity with other parts of the brain.
The controversial treatment, which has been used clinically for more than 70 years, involves anaesthetising a patient and electronically inducing a seizure. This is the first time researchers have uncovered the mechanics of how the therapy works.
Researchers from the University of Aberdeen claim the electroconvulsive therapy (ECT) could pave the way for more effective treatment of those suffering from severe depression.
Scientists decided to investigate this further by experimenting with ECT by ‘turning down’ an overactive connection between certain parts of the brain that control mood, thought and concentration.
The study, published in the Proceedings of the National Academy of Sciences, involved observing the brain connectivity of six men and three women being treated for depression at the Royal Cornhill Hospital in Aberdeen.
All nine of the participants had failed to respond to prescribed antidepressants and underwent the ECT twice a week for a month until their symptoms eased.
Scientists saw a change in the patients' MRI brain scans and noted a difference in how the brain cells that are linked to depression connected to each other. They claim that the ECT is the reason for the patients’ significant improvement in depression symptoms.
Professor Ian Reid from the study, said as reported by the Press Association: "ECT is a controversial treatment, and one prominent criticism has been that it is not understood how it works and what it does to the brain.
"However, we believe we've solved a 70-year-old therapeutic riddle because our study reveals that ECT affects the way different parts of the brain involved in depression connect with one another.
"For all the debate surrounding ECT, it is one of the most effective treatments not just in psychiatry but in the whole of medicine, because 75% to 85% of patients recover from the symptoms.
"Over the last couple of years there has been an emerging new perspective on how depression affects the brain.
"This theory has suggested a 'hyperconnection' between the areas of the brain involved in emotional processing and mood change and the parts of the brain involved in thinking and concentrating.
"Our key finding is that if you compare the connections in the brain before and after ECT, ECT reduces the connection strength between these same areas - it reduces this hyperconnectivity.
"For the first time we can point to something that ECT does in the brain that makes sense in the context of what we think is wrong in people who are depressed.
"As far as we know no-one has extended that 'connectivity' idea about depression into an arena where you can show a treatment clearly treating depression, changing brain connectivity.
"And the change that we see in the brain connections after ECT reflects the change that we see in the symptom profile of patients who generally see a big improvement."