Personally I've turned down ECT twice because of the side effects and risks. However, I know several people that have gone through with it and have done the full round of ECT treatments.
I can think of one person in particular that did awful with them - he was extremely forgetful, heartless, tired all the time, confused, he even started getting seizures ( outside of ECT - which he never had before). He was extremely depressed and even remained in hospital for a year during and following treatment.
4 other people I have in mind have gone through treatment and have had a very little positive effect from them, but not too many negative consequences. They showed very little improvement.
1 more person I have in mind went through with ECT and stayed out of hospital and was doing well for approximately 20 years!
So, thats all I can really tell you so you need to be the judge, do what feels right.