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

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.