Background: Subsyndromal depressive symptoms are highly prevalent and associated with substantial impairments of daily function in the general population. Depressive symptoms are common in schizophrenia. However, few studies have examined the relationship of functioning and well-being to the presence of depressive symptoms in schizophrenia.
Method: 202 middle-aged or elderly outpatients with schizophrenia (DSM-III-R or DSM-IV criteria) were categorized by severity of depressive symptoms on the Hamilton Rating Scale for Depression (HAM-D) using previously validated cutoff points, i.e., HAM-D total score < or = 6 (low), from 7 to 16 (medium), and > or = 17 (high). We also assessed severity of positive and negative symptoms, movement disorders, neurocognitive performance, daily functioning, and health-related quality of well-being with standardized measures.
Results: A total of 11.4% of patients had HAM-D scores > or = 17, and 56.4% had HAM-D scores from 7 to 16. Even after adjusting for severity of other psychopathology, patients with more severe depressive symptoms had significantly worse everyday functioning (p < .02), except for physical functioning, and health-related quality of well-being (r = -.365, p < .001) than did those with lower HAM-D scores. These differences were unrelated to those in demographics, extrapyramidal symptoms, tardive dyskinesia, neurocognitive performance, or number of physical illnesses.
Conclusion: The results suggest the importance of evaluating schizophrenia patients for the presence of depressive symptoms. Effectiveness of adjunct treatment of depressive symptoms with antidepressants and psychosocial management in improving functioning of schizophrenia patients deserves further study.