I feel like some people seek out such materials, movies and books that are profound, depressing and deep, because they might conciously or subconsciously align to the message inside of them - whether it's the characters' emotions or the sad nature of the story. Often depressed people, or very emotional people, will like these enthralling, deep and sadder stories and movies since they can personally identify with them and almost seek refuge in them. I've read about this and feel this way myself. If you have very deep, intuitive emotions, maybe a more melancholic side of yourself is being reflected back in this intense stories and you just really like how you can identify with them. I'm a depression sufferer too so I think I get you there.

So, the question is, like I struggle with too, how does one really avoid such awesome things one identifies with? I personally identify very intensely to movies like Gia and books like the Anne Sexton collected poems since such materials are very profound, deep, tear-jerking, and can allow me to see parts of my own life, my own deeper emotions, and have an outlet to express my supressed sadder emotions. Yet it's important for me to know when is a good time to expose myself to stuff like this. I think that might be important for you, too. Just judge your mood, and how high or low it is. I usually avoid reading or watching such things, despite them being favorites, because they'll only make my moods lower. It's tempting to do it anyway but I really try to force myself to avoid them.

If this particular schizophrenia book is too much for you, just don't read it anymore, for now. Take a break periodically when reading it. Only read 35-50 pages per week. Or just take a break from it totally for a bit. See what happens, and if you pick it up again and it is just too much for you, don't go back to it.