Interrelationships of psychiatric symptom severity, medical comorbidity, and functioning in schizophrenia

Objective: This cross-sectional study aimed to evaluate the interrelationships of psychiatric symptom severity, medical comorbidity, and psychosocial functioning in a sample of patients with schizophrenia by utilizing the baseline data from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE). Methods: This study utilized baseline data from a multisite trial of antipsychotic pharmacotherapy, which collected data from 1,460 patients with schizophrenia at more than 50 sites in the United States between 2001 and 2003. Bivariate correlations were used to evaluate associations between schizophrenia symptoms and medical comorbidity, and multivariate regression models were used to determine the independent association between medical comorbidity and psychosocial functioning. Results: Of the 1,424 participants in the study sample, 58 percent had at least one medical condition: 20 percent had hypertension, 11 percent had diabetes mellitus, and 9 percent had four or more medical conditions. Medical comorbidity was associated with poorer neurocognitive functioning and greater depressive symptoms. The number of medical conditions was not associated with more severe schizophrenia symptoms. Both the number of medical conditions and physical health status were only weak correlates of psychosocial functioning. Conclusions: In this sample of persons with schizophrenia, medical comorbidity was associated with depression and neurocognitive impairment but was a weaker correlate of psychosocial functioning or employment status than psychotic symptoms, depression, and neurocognitive impairment.