Early symptoms come and go?

My son is 16 years old and has just started Abilify. For the past 2 years he has been depressed, socially anxious and has had episodes of psychotic writings. He has also said in a letter that he was demon posessed for 6 months.He does not admit to seeing or hearing voices....but he is not always truthful. He thinks everyone hates him...and does not like going to school since everyone is "against him". He also can not focus on anything anymore....too much noise. Also when he reads, the words are jumbled up on the page. He also can not carry a conversation well....can't focus. My question is ....the doctor is leaning towards sz....but right now he seems so "normal". Is this something that comes and goes in the early stages? Thanks for any advice.