6.89 DEFINING SYMPTOM DIMENSIONS AND SUBTYPES IN CHILDHOOD-ONSET SCHIZOPHRENIA

Objectives: Clinical experience and recent research suggest that non-classical subgroups exist within the schizophrenia patient population (e.g., deficit schizophrenia). Childhood onset schizophrenia (COS) is a rare and severe form of the disorder. This study reports on symptom dimensions and subtypes in a COS population. Methods: Since 1990, patients nationwide were screened for study admission based on medical history and symptoms. Inpatient clinical observation during a 3-week medication free period was used to make a COS diagnosis. We used psychiatric symptom rating data from admission of 90 COS patients to perform first level exploratory factor analysis. The resulting composite scores were used in second level factor analysis to define integrated symptom dimensions. Linear regression was used to assess the relationship between dimension composite scores and other clinical and demographic variables. K-means cluster analysis was done using the dimension composite scores to form patient clusters, which were then compared to each other and to adult research. Results: Second level factor analysis revealed three overarching symptom dimensions in COS data: 1) negative; 2) disorganized; and 3) mixed distress and delusional symptoms. Linear regression showed the negative factor was significantly correlated with age of onset (b=3.85, p