Diagnostic clusters associated with an early onset schizophrenia diagnosis among children and adolescents.

Objective: 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.

Methods: 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.

Results: 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.

Conclusion: 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.