Dimensional symptom severity and global cognitive function predict subjective quality of life in patients with schizophrenia and healthy adults

Over the last several decades Quality of Life (QoL) has become increasingly important as an indicator of treatment outcomes; particularly in schizophrenia spectrum disorders because of its close association with functional disability. Numerous studies seeking to elucidate the factors that contribute to QoL in this population have implicated both symptom severity and cognition in determining QoL but the findings have been mixed. The critical factors that appear to impede the lack of consensus in the extant literature examining determinants of QoL include the heterogeneity of the samples and measures examined as well as medication effects across different studies. Thus, the present study sought to address some of these issues by examining the relationship between subjective QoL and both symptom severity and cognitive function in a relatively homogeneous patient sample of patients and a community control sample assessed for dimensional symptom severity. Our results suggest that both global cognitive function and psychiatric symptoms have a significant impact on the subjective QoL of both people with schizophrenia spectrum disorders and psychiatrically healthy adults. Specifically, we found that a global index of cognition as well as self-reported avolitional and depressive symptoms were significantly predictive of QoL in both samples. These findings highlight the importance of addressing cognitive, depressive and avolitional symptoms in the treatment of patients with schizophrenia spectrum disorders and suggest that improvements in these domains may have a meaningful impact on their overall QoL.