Identifying differences in biased affective information processing in major depression

This study investigates the extent to which participants with major depression differ from healthy comparison participants in the irregularities in affective information processing, characterized by deficits in facial expression recognition, intensity categorization, and reaction time to identifying emotionally salient and neutral information. Data on diagnoses, symptom severity, and affective information processing using a facial recognition task were collected from 66 participants, male and female between ages 18 and 54 years, grouped by major depressive disorder (N=37) or healthy non-psychiatric (N=29) status. Findings from MANCOVAs revealed that major depression was associated with a significantly longer reaction time to sad facial expressions compared with healthy status. Also, depressed participants demonstrated a negative bias towards interpreting neutral facial expressions as sad significantly more often than healthy participants. In turn, healthy participants interpreted neutral faces as happy significantly more often than depressed participants. No group differences were observed for facial expression recognition and intensity categorization: The observed effects suggest that depression has significant effects on the perception of the intensity of negative affective stimuli, delayed speed of processing sad affective information, and biases towards interpreting neutral faces as sad. (c) 2007 Elsevier Ireland Ltd. All rights reserved.