T68. DIFFERENT INFLUENCES OF INTELLECTUAL FUNCTIONING AND COGNITIVE PERFORMANCE TO FUNCTIONAL OUTCOMES IN SCHIZOPHRENIA AND HEALTHY CONTROLS

• Published in: Schizophrenia bulletin 2018-04, Vol.44 (suppl_1), p.S140-S140
• Main Authors: Czepielewski, Leticia, Gama, Clarissa, Carter, Cameron, MacDonald, Angus, Gold, James, Silverstein, Steven, Barch, Deanna
• Format: Article
• Language: English
• Subjects: Abstracts
• ISSN: 0586-7614; 1745-1701
• DOI: 10.1093/schbul/sby016.344

Abstract Background Individuals with schizophrenia (SZ) have marked functional impairments in wide range of domains, such as employment, independent living and interpersonal relationships. Several clinical, cognitive and psychological factors have been shown to predict functional outcomes. However, current pharmacological and psychosocial treatments have failed to rehabilitate patients, which indicates that the mechanisms of functional outcomes are not completely clear. Therefore, we aimed to better understand the relationship between intellectual and cognitive performance to functional outcome of subjects with SZ compared to unaffected individuals. Considering the neurodevelopmental course of SZ, our hypothesis was that premorbid crystallized IQ would interact with cognition to influence functionality. Methods We included 188 individuals with confirmed diagnosis of SZ and 268 unaffected subjects (HC) from two separate multisite studies conducted by the Cognitive Neuroscience Test Reliability and Clinical Applications for Schizophrenia (CNTRACS) consortium. We used the following variables for the analysis: a) Estimated crystallized premorbid intellectual functioning (IQ): Wechsler Test of Adult Reading (WTAR); b) Cognitive performance: Dot Probe Expectancy task (DPX) and Relational and Item-Specific Encoding task (RISE) from CNTRACS; c) Functional capacity: UCSD Performance-based Skills Assessment – Brief (UPSA-B). We conducted linear regressions to predict functional outcome considering demographic, intellectual, and cognitive variables, as well as the interaction between cognition and IQ in participants with SZ and HC separately. Results Participants with SZ had worse cognitive performance and premorbid IQ, and poorer functional outcome compared to HC. For the prediction of UPSA-B, the regression model that included cognition and IQ as predictors and age and parental SES as covariates was significant in SZ (F(4, 124) = 8.473, p < .001, Adj. R2 = .189), with the both variables showing significant main effects: IQ (β = .311, t = 3.324, p = .001) and cognition (β = .216, t = 2.630, p = .0010). When we included the IQ x cognition interaction (F(5, 123) = 7.035, p < .001, Adjusted R2 = .191), it did not significantly improve the model (F = 1.224, p = 0.27), and the interaction was not significant (β = -.11, t = -1.106, p = .27). In HC, the regression model with only main effects was similar to what was seen in SZ (F(4,313) = 27.62, p < .001, Adj. R2 = .25), w