I have had a great many severe, schizophrenic experiences over 20 years. It's interesting because I'm very smart which goes along well with it, I remember them well when you are supposed to remember them, and it's like having more than two brains because you've got your consciousness, your made up one, and the union of the two.
This book marks a compact description of such experiences that I believe any audience can enjoy. A teenager will be just fine.
Some symptoms to wet your appetite: hallucinations some huge some long, delusions, thought broadcasting, dictation of what I was doing, own lexicon, people reading my mind, predictions, God/King/prophet complex, interesting creative detail, and long and short memory problems.