What's the Name of That Book??? discussion

The story starts with a boy living in an asylum, he isn't a patient but his mother was and had killed herself by jumping off the building. He befriends a girl who is from a well off family. Something happens that the boy is admitted to the asylum and given electric shocks while the girl watches helpless. Then he discovers he has some kind of mental power and his mother did as well. She was not insane but part of a resistance fighting the dystopian society. Rebels from the outside break the boy and girl out of the city and they join the fight.

I read this book when I was taking a ya lit class (2008ish). It was a hardcover book and part of a series I'm not sure was finished or not.

The title of the book has the word "hollow" in it somewhere. It is the first book in part of a series, but I cannot remember if "hollow" was in the book or series title. The cover of the copy I read was black and purple; a silhouette of a boy could be seen with lightning in the sky.

Thanks for any and all help!

The Hollow Kingdom

a book titled Hollow (too many results in search): https://www.goodreads.com/book/show/1...

The Dark and Hollow Places

Probably not, but: Hollow Earth

None of those titles I'm afraid. :(
The series was more sci-fi than magical- there was technology, maybe par with the 1920s.

The Hollow People ?

YES! That is it, thank you Lou!