The Wasp Factory question

Looking for books for a young man who is currently mentally ill - in a mental hospital with anti-psychotic medication etc. He is intelligent (top of class a few years ago in high school) but due to current condition finding it hard to focus on anything for very long. He was a voracious reader as a teen of challenging stories but probably shouldn't go there, nor into mental disorder stories - eg, before this mental health episode I would recommend Iain Banks because they are so good but not now. As he's a young adult trite, children's stories wouldn't be of much interest, nor would period drama.

Perhaps people here have recovered from a similar experience and can remember books that were simple enough to engage with but, were interesting to help get their intellect going again.