title: Early onset psychotic disorders: diagnostic stability and clinical characteristics.
abstract: OBJECTIVE
  To examine the clinical features and diagnostic stability of early-onset psychotic disorders.
  
  
  METHODS
  These data are from a two-year longitudinal prospective study of youth with psychotic disorders. Standardized diagnostic assessments are administered at baseline and at one and two-year's follow-up.
  
  
  RESULTS
  Fifty-one subjects have been recruited to date; 18 with schizophrenia, 14 with bipolar disorder, 7 with schizoaffective disorder, 1 with an organic psychosis, and 11 subjects whose symptoms where either questionable and/or did not meet diagnostic criteria for another disorder (classified as psychosis nos). Thirty-nine subjects were reassessed at year one, twenty-four at year two. Three subjects have been lost to follow-up. The study diagnosis was the same as the first onset diagnosis (prior to entering the study) in 50% of subjects. Over the two-year period of the study, the diagnosis remained unchanged in over 90% of subjects. Subjects with schizophrenia had higher ratings of premorbid impairment, including social withdrawal and dysfunctional peer relationships, than those with bipolar disorder. At the one-year follow-up, subjects with schizophrenia and schizoaffective disorder had significantly higher rates of delusions, bizarre behavior, and negative symptoms than those with bipolar disorder. Subjects with bipolar disorder tended to have cyclical courses, whereas those with schizophrenia and schizoaffective disorder were often chronically impaired. Subjects with psychosis nos had higher rates of dissociative symptoms and histories of child maltreatment.
  
  
  CONCLUSIONS
  Early-onset psychotic disorders can be reliably diagnosed using standardized assessments and are stable over a two-year period. Compared to bipolar disorder, schizophrenia is associated with a poorer premorbid history, and persistent positive and negative symptoms.
authors.affiliation: University of Washington's Department of Psychiatry, Seattle 98195, USA. drjack@u.washington.edu
authors.forename: J
authors.initials: J
authors.lastname: McClellan
authors.forename: C
authors.initials: C
authors.lastname: McCurry
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000523:psychology*; D012720:Severity of Illness Index