Relationship of subjective quality of life with symptomatology, neurocognition and psychosocial functioning in first-episode psychosis: a structural equation modelling approach

Abstract

Subjective quality of life (SQoL) represents an important outcome of psychotic disorders. However, determinants of SQoL and their complex inter-relationships in the early course of illness remain to be clarified. Association between neurocognitive impairment and SQoL in first-episode psychosis (FEP) is understudied. This study employed structural equation modeling (SEM) to examine relationships among SQoL, depressive, positive and negative symptoms, neurocognition, and psychosocial functioning in FEP patients. Three hundred and forty-seven patients aged 25–55 years presenting with FEP to early intervention program in Hong Kong were recruited. Assessment encompassing symptom profiles, psychosocial functioning and a battery of neurocognitive tests were conducted. SF-12 mental component summary scores were computed as the primary measure of SQoL. Our correlation analyses revealed differential relationships between negative symptom subdomains and SQoL, with amotivation, but not diminished expression, being related to SQoL. Final SEM model yielded a good model fit (comparative fix index = 0.94; root mean square error of approximation = 0.05; standardized root mean square residuals = 0.07) and demonstrated that depression, positive symptoms and psychosocial functioning were directly associated with SQoL, with depression showing the strongest effect. Amotivation, neurocognition and positive symptoms had an indirect effect on SQoL via the mediation of psychosocial functioning. This study affirms depression as a critical determinant of subjective mental wellbeing, and underscores an intermediary role of psychosocial functioning in linking amotivation, neurocognitive impairment and positive symptoms to SQoL in FEP patients. Depression and functional impairment thus constitute as crucial therapeutic targets for improvement of SQoL in the early illness stage.