Biases in processing of mood-congruent facial expressions in depression.

Cognitive models of depression suggest that depressed individuals exhibit a tendency to attribute negative meaning to neutral stimuli, and enhanced processing of mood-congruent stimuli. However, evidence thus far has been inconsistent. In this study, we sought to identify both differential interpretation of neutral information as well as emotion processing biases associated with depression. Fifty adult participants completed standardized mood-related questionnaires, a novel immediate mood scale questionnaire (IMS-12), and a novel task, Emotion Matcher, in which they were required to indicate whether pairs of emotional faces show the same expression or not. We found that overall success rate and reaction time on the Emotion Matcher task did not differ as a function of severity of depression. However, more depressed participants had significantly worse performance when presented with sad-neutral face pairs, as well as increased reaction times to happy-happy pairs. In addition, accuracy of the sad-neutral pairs was found to be significantly associated with depression severity in a regression model. Our study provides partial support for the mood-congruent hypothesis, revealing only a potential bias in interpretation of sad and neutral expressions, but not a general deficit in processing of facial expressions. The potential of such bias in serving as a predictor for depression should be further examined in future studies.