Schizophrenia has a lifetime prevalence of about 0.3 - 0.7%, depending on cultural settings, ethnic groups or countries, as well as the epidemiological rigor of each community in recording and reporting observed cases. The prevalence by sex varies according to age, being more frequent in males in early stages, around the age of onset of the disease, around 20 years of age, and then equalizing with females in which the age of onset is later, characterized by the presence of hallucinations, delusions, disorganization of thought and behavior, as well as affective impoverishment and cognitive impairment. These symptoms lead in most patients to a profound deterioration of personality and social functioning and entail significant suffering for both the patient and his or her environment and a great economic burden for society.This clinical heterogeneity probably reflects pathophysiological and etiological heterogeneity.