Comparison of Ambulatory and Retrospective Measures of Depression in Individuals with Schizophrenia

Abstract

Experience sampling method (ESM) has been shown to be a valid and reliable method of assessing psychotic symptoms in patients diagnosed with schizophrenia as well as depressive symptoms in patients with mood disorders, but has not yet been used to assess depressive symptoms in individuals diagnosed with schizophrenia. The aim of this study was to examine the validity of assessing depressive symptoms using a computerized ESM method in individuals diagnosed with schizophrenia as compared to a retrospective measure of depression. Individuals with a diagnosis of schizophrenia completed computerized ESM ratings for two days. Additionally, they completed retrospective symptom measures of depression as well as neuropsychological measures. There was a significant correlation between the ESM measure of depression and BDI-II, (r (40) = .606, p < .001) in individuals with schizophrenia. However, once variance due to episodic memory was controlled, the relationship between the BDI-II and ESM was only a trend, (pr (34) = 0.313, p = .092). Given that our participants with schizophrenia were shown to have impaired episodic memory function, and that the BDI-II relies on retrospective recall, whereas ESM does not, we conclude the ESM measure might serve as a more accurate measure of depressive mood in individuals with schizophrenia.