That's the way it happened with my friend's son. His life was in termoil at home, so he travelled from Cornwall to mine and said he wanted to learn signwriting. He got very down because he thought he couldn't do it (it takes 7 years basic training) then I saw that he joined the Territorial Army. He didn't get on very well there became very depressed and finally went home.
He was sitting very quietly one day reading a book when he suddenly flew into a rage and began hitting out at his father. Luckily his father was stronger than him and managed to restrain him. But that marked the visible beginning of his illness. Now he is into his 50's. Not cured but controlled with drugs. Very sad. We used to go cliff climbing together and for walks in woods as we both liked nature. But he just retreated into himself and his own imaginary world. Now whenever he hears a helicopter he thinks the police are coming to get him.
It is a dreadful illness but it can be controlled with drugs however, as we know even today the drugs nearly always cause side effects which isn't a pleasant way to have to live.
It's true violent anger is a symptom of uncontrolled schizophrenia, although some schizophrenics are given to extreme violence and others never hurt anyone but themselves. For many the symptoms subside as a sufferers grows older, what they used to call 'burned out', even dangerous PS sufferers could become calm with age.
I cannot understand how schizophrenics who commit crimes while suffering a psychotic episode are held responsible for their crimes. It's a tragedy for all concerned imo.
