Childhood-onset schizophrenia (COS; defined as onset by age 12) is a rare phenotypic variant of adult-onset schizophrenia. A longitudinal MRI study of COS has been ongoing at the NIMH since 1990. The diagnosis is made using unmodified DSM IIIR/IV criteria and, in most cases, after a drug-free inpatient observation. The COS cases (n=102 to date at the NIMH) clinically resemble poor outcome Adult Onset Schizophrenia (AOS) cases, in that all phenomenological (Asarnow et al., 2001), family (R. Nicolson et al., 2003) and neurobiological (Asarnow et al., 1994; Gochman et al., 2004; Rapoport, Addington, Frangou, & Psych, 2005) studies in COS show similar findings as in the AOS, suggesting continuity between these two forms of the illness.
