Impaired meaning-based cognitive skills are specifically associated with poorer subjective quality of life in schizophrenia

Abstract

Cognitive impairment is characteristic of schizophrenia but the nature and severity often differ between patients and the relationship with subjective quality of life (sQOL) is inconsistent. This study sought to better characterise the cognition-sQOL relationship in schizophrenia by 1) examining associations between factor analysis-derived cognitive domains and sQOL, 2) investigating if these domains independently predicted sQOL, and 3) exploring if clinical, demographic and functional variables moderated any significant relationships. 47 schizophrenia/schizoaffective disorder patients and 48 healthy controls were assessed. QOL was measured using the Lehman’s QOL Interview. Composite scores were created to represent objective QOL and sQOL, and factor analysis was used to determine cognitive domains from 14 cognitive tasks. Three cognitive domains were derived: visuospatial planning, verbal linguistic and inhibition switching. Tasks comprising the verbal linguistic cognitive domain were significantly associated with and predicted sQOL. Moderation analyses revealed that the direction of this relationship differed between patients and healthy controls, and may be moderated by positive symptom severity in patients. In conclusion, meaning-based (e.g. verbal-linguistic) cognitive abilities may be most closely related to sQOL in schizophrenia. Symptomatology may also impact this relationship, with worsening sQOL among those with more intact verbal-linguistic processing and persistent positive symptoms. These patients may therefore be at greater risk for poor sQOL, but may be more motivated and capable of engaging in and benefiting from offered psychosocial interventions.