The relationship between residual symptoms of depression and emotional information processing

Introduction: Depression is associated with cognitive deficits, social withdrawal and high risk of relapse. Several factors have been proposed as pertaining to increasing the risk of relapse, including a bias in emotional information processing. This study was carried out to examine the relationships between major depressive disorder (MDD), level of depressive symptoms and bias in emotional effortful information processing. Method: Nineteen patients diagnosed with recurrent MDD and 19 matched controls were tested with an experimental visual face-in-the-crowd paradigm including sad, happy and neutral information. The patients were tested on average 9 months after hospitalization. At testing, the patient group showed an overall decrease in depression severity symptom load as measured on the Hamilton Depression Rating Scale (HDRS), but with variable symptom load. Results: Reaction time (RT) did not vary between patients and controls in the visual face-in-the-crowd task or on a measure of psychomotor speed. In the patient group, symptom load was related to longer RTs when negative targets were shown against positive distractors. The results revealed a specific bias in response to negative emotional information. Conclusions: Symptom load in the patient group is related to a negative bias in emotional information processing that cannot be explained by psychomotor retardation.