The response to medication is always best during the first psychotic break and usually diminishes with delays and relapses. It is very important to treat early with atypical medication and avoid relapses because of this. If you are new to schizophrenia you might want to read one of the following pamphlets written by the American Psychiatric Association, the National Institute for Mental Health, and the Royal College of Psychiatrists respectively. The most succinct article I've read on the internet is Dr. Ben Green's Overview . A period of severe depression sometimes precedes the first emergence of schizophrenia in late adolescence.
Substance abuse is also quite common before the first psychotic break.
The prodromal symptoms are a period of lower functioning that immediately precedes a psychotic break. It is usually only recognized in hindsight though. A psychotic break is characterized by a lot of reality distortion and disorganization. Schizophrenia is not a simple illness. The chart indicates the degree of social dysfunction symptoms cause, by the number of arrows pointing to the center.