This has to be one of my favourite sub-genres; psychological science fiction. This is up there with the likes of A Scanner Darkly and More Than Human. These are the sort of SF books that I would recommend to those who look down on the genre.
This book explores such themes as the nature of intelligence, the effects of intelligence on the way you see others and the world around you, as well as social attitudes towards people with mental problems.
The narrative structure is a series of progress reports, written by the protagonist, detailing his experiences throughout his period of experimental treatment. Thus we have a simple but clever way of portraying the changes in his perception and mental abilities which I don't think would have been as effective had it been written in the third person.
One of the fascinating things about this story is seeing the way the attitudes of others towards him changed as he became more intelligent (not always for the better) and the way his view of others changed as he surpassed them. This has certainly changed the way I think about people with mental problems. A great example of how SF can give a writer tools for examining people and society that other genres lack.