Introduction Schizophrenia is a particularly devastating psychiatric disorder. Although extremely rare before the age of 10, the incidence of schizophrenia rises steadily through adolescence to reach its peak in early adult life. Early-onset schizophrenia (EOS) arising in childhood and adolescence is now accepted to be clinically and biologically continuous with the adult-onset disorder. The most striking differences associated with early-onset appear to be the greater clinical severity, more frequent and more pronounced early neurodevelopment abnormalities, and poorer treatment response. The current concept of EOS evolved from a different perspective held during much of the 20th century. Until the early 1970s the term childhood schizophrenia was applied to children who would now be diagnosed with autism. Until the 1990s, there was doubt about the validity of diagnosing schizophrenia in children and younger adolescents. However, in DSM-III and ICD-9 the separate category of childh...

 CHAPTER 5.3 CHILDHOOD-ONSET SCHIZOPHRENIA AND OTHER EARLY-ONSET PSYCHOTIC DISORDERS ANNA E. ORDÓÑEZ AND NITIN GOGTAY BACKGROUND Psychotic disorders are rare in children although transient psychotic experiences are more common in otherwise healthy children than generally recognized (1–3). As is often the case with other very early-onset illnesses, psychotic disorders in children are usually more severe than their adult counterparts (4), and the disruption of cognitive and social development as well as the burden to the family can be devastating. Systematic research in this area was initially limited by diagnostic uncertainty and the general lack of knowledge about the psychotic processes in children (5). History of Childhood-Onset Psychoses Although the existence of childhood schizophrenia was recognized early in the twentieth century (6), the term psychosis was used so broadly in children that a spectrum of behavioral disorders and autism were grouped together under the category o...