Aim: In the clinical high-risk (CHR) state for psychosis, both negative symptoms and lower cognitive function have been associated with poorer daily functioning. Recent evidence suggests that negative symptoms share overlapping variability with cognition and may partially mediate the relationship between cognition and functioning. However, the nature of this overlap is unknown, and the reverse mediation model remains untested leaving the precise nature of these associations unclear.
Methods: In order to clarify these relationships, a sample of community-dwelling youth meeting CHR criteria was collected from a specialty CHR clinic (n = 91, mean age = 21, 63% male). Bootstrapping methods were then applied in a mediation analysis to test both negative symptoms and cognition as independent variables and mediating variables predicting social and role functioning in CHR individuals. Canonical correlation analysis was used to characterize the overlapping variability between negative symptoms and cognition.
Results: Support for a primary role of negative symptoms in predicting functioning and cognition was observed. Canonical correlation revealed a single dimension of overlap between the two symptom types (r = .62), represented by a strong correlation between negative symptoms in general and tasks involving verbal working memory, vigilance and social cognition specifically. A single cognitive factor composed primarily of these tasks was found to predict role functioning (adjusted R 2 = .04).
Conclusions: The results highlight the importance of considering specific cognitive mechanisms overlapping with negative symptoms in research and rehabilitative practice in CHR populations, as well as the primary importance of targeting negative symptoms.
Keywords: clinical high risk; cognition; functioning; negative symptoms; psychosis.
© 2019 John Wiley & Sons Australia, Ltd.