I don't know, I've had it done (by choice, not under involuntary commitment of any kind), and my brain feels pretty intact.
It's possible that it has no useful effect on people and all the (mostly historical, for reasons the article mentions) studies of its efficacy are fundamentally flawed, but people do keep using it outside of involuntary contexts, when the desperation is strong enough and enough other treatments haven't worked, and some of them find it quite effective.