information:classification, structural:expansion
Onset

Onset may happen suddenly or may occur after the slow and gradual development of a number of signs and symptoms, a period known as the prodromal stage. Up to 75% of those with schizophrenia go through a prodromal stage. The negative and cognitive symptoms in the prodrome stage can precede FEP (first episode psychosis) by many months and up to five years. The period from FEP and treatment is known as the duration of untreated psychosis (DUP) which is seen to be a factor in functional outcome. The prodromal stage is the high-risk stage for the development of psychosis. Since the progression to first episode psychosis is not inevitable, an alternative term is often preferred of at risk mental state. Cognitive dysfunction at an early age impacts a young person's usual cognitive development. Recognition and early intervention at the prodromal stage would minimize the associated disruption to educational and social development and has been the focus of many studies.