T72. COGNITIVE CLUSTERS IN FIRST-EPISODE PSYCHOSIS AND THEIR RELATIONSHIP TO SYMPTOMATOLOGY AND DEVELOPMENTAL SCHOLASTIC PERFORMANCE

BACKGROUND: Groups with differential levels of cognitive impairment are increasingly recognized among patients with schizophrenia spectrum disorders. Using cluster analytical techniques, this study sought to explore cognitive clusters in a sample of first-episode psychosis patients and compare levels of symptomatology as well as childhood and adolescent scholastic performance between the resultant groups. METHODS: Data from 105 first-episode psychosis patients (n=56 with schizophrenia, n=13 with schizoaffective disorder, depressed type, n=36 with schizophreniform disorder) (mean age=22.06, SD=3.79) in the UCLA Aftercare Research Program were used for this analysis. Cognition was assessed using a modified beta version of the MATRICS Consensus Cognitive Battery which consisted of 16 tasks across seven cognitive domains. Symptomatology and developmental scholastic performance were assessed using the Brief Psychiatric Rating Scale and the Cannon-Spoor Premorbid Adjustment Scale respectively. Hierarchical cluster analysis with Ward’s method and squared Euclidean distance was conducted, confirmed by discriminant function analysis and optimized with k-means clustering. Stability of the solution was evaluated through split-sample (random 80% and 70% samples) and alternate method (average linkage method) replication via Cohen’s κ analysis. RESULTS: Three clusters were identified: most impaired (n=27), moderately impaired (n=41) and good (n=37). Controlling for multiple comparisons, one-way ANOVAs revealed no significant differences in symptomatology between the groups (p>.008). Significant differences were observed for scholastic performance at three different developmental stages: childhood (p<.0001), early adolescence (p<.0001) and late adolescence (p<.0001), with the good group demonstrating significantly better scholastic performance than both the moderately impaired and most impaired groups (who did not significantly differ from each other) at all three stages. DISCUSSION: The findings add to growing evidence that cognitive clusters in FEP mirror that of later-stage schizophrenia. Cognitive clusters were not associated with differences in symptom severity, but reflected differing levels of premorbid scholastic performance during the developmental years. This suggests that performance at school may not just be a risk factor for developing schizophrenia, but also related to the severity of impairment and potentially prognosis.