Depression in schizophrenia: methodological artifact or distinct feature of the illness?

In schizophrenia, there is a conceptual overlap between depressive and negative symptoms. This study examined the dimensional structure of depressive symptoms and their overlap with negative symptoms in a large sample of older medicated schizophrenia outpatients. Self-reported depression was obtained with the Beck Depression Inventory-II (BDI-II). Three components from this scale (i.e., dysphoria, psychosomatic and regret domains) showed excellent factorability and good consistency. However, adequate construct validity and correlates with outcomes were found for the dysphoria and regret domains, but not for the total score or the psychosomatic domain. Thus, the evaluation of domains within the BDI-II provides a more pure and clinically-relevant assessment of depressed mood in schizophrenia than the use of this scale as a whole.