Electro-shock therapy.... or electro-convulsive treatment ~

Medical professionals have said they have no knowledge as to how it works. Where did they get the idea, then, to apply electricity to a body to treat a psychological (a spiritual) problem?

https://cdn.masto.host/mastjohn1126com/media_attachments/files/116/172/481/144/781/848/original/818fd9c7cac79170.mp4

People that suffer from convulsions would say the seizure itself was the problem. So it is ironic that causing a seizure, externally, could somehow be a good thing. Or is it good?