title: Diagnostic clusters associated with an early onset schizophrenia diagnosis among children and adolescents.
abstract: Given the greater severity and chronicity of psychiatric disorders that first declare in individuals under the age of 18, early onset schizophrenia (EOS) and its association with co-occurring psychiatric conditions deserve further investigation.
  
  
  
  Cluster and discriminant analyses were used to examine the heterogeneity of children and adolescents diagnosed with schizophrenia in 1 statewide system of care. A retrospective cohort design was employed, using South Carolina's (USA) Medicaid claims dataset covering outpatient and inpatient medical services between January, 1999 and December, 2013 to identify patients ≤17 years of age.
  
  
  
  Among the 613 EOS patients selected, 3 main clusters of ICD-9 psychiatric diagnoses were identified: (1) older children with schizophrenia coaggregated with a spectrum of mood/emotional dysregulation conditions; (2) younger children with coaggregated schizophrenia, mental retardation/intellectual disability or autism spectrum disorders; and (3) older children with schizophrenia and significantly fewer diagnosed co-occurring conditions. Externalizing/disruptive behavior disorders (i.e., attention deficit hyperactivity disorder, conduct disorder, and oppositional defiant disorder) were significantly associated with Clusters 1 and 2.
  
  
  
  Symptom patterns plus age of first diagnosis are important differentiators of EOS subgroups in this cohort. Earlier recognition of psychiatric symptom/syndrome patterns that frequently co-occur may enable clinicians to stratify/tailor treatment interventions.
authors.affiliation: Department of Neuropsychiatry, University of South Carolina School of Medicine, Columbia, South Carolina, USA.
authors.forename: Jeanette M
authors.initials: JM
authors.lastname: Jerrell
authors.affiliation: Departments of Psychiatry and Pharmacology, University of Toronto, Toronto, Canada.
authors.forename: Roger S
authors.initials: RS
authors.lastname: McIntyre
authors.affiliation: Department of Health Management and Informatics, Office of Research Biostatistics Research and Design Unit, University of Missouri School of Medicine, Columbia, Missouri, USA.
authors.forename: Chelsea B
authors.initials: CB
authors.lastname: Deroche
mesh_terms: D000293:Adolescent; D000367:Age Factors; D017668:Age of Onset; D002648:Child; D016000:Cluster Analysis; D015897:Comorbidity; D016208:Databases, Factual; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D008297:Male; D008484:Medicaid / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012559:Schizophrenia / Q000175:diagnosis* / Q000453:epidemiology*; D013022:South Carolina / Q000453:epidemiology; D014481:United States
keywords: adolescent onset schizophrenia; childhood onset schizophrenia; co-occurring psychiatric disorders; neurodevelopmental continuum