Facial perception bias in patients with major depression.

This study used a morphed categorical perception facial expression task to evaluate whether patients with depression demonstrated deficits in distinguishing boundaries between emotions. Forty-one patients with depression and 41 healthy controls took part in this study. They were administered a standardized set of morphed photographs of facial expressions with varying emotional intensities between 0% and 100% of the emotion, in 10% increments to provide a range of intensities from pleasant to unpleasant(e.g. happy to sad, happy to angry) and approach-avoidance (e.g. angry to fearful). Compared with healthy controls, the patients with depression demonstrated a rapid perception of sad expressions in happy-sad emotional continuum and demonstrated a rapid perception of angry expressions in angry-fearful emotional continuum. In addition, when facial expressions shifted from happy to angry, the depressed patients had a clear demarcation for the happy-angry continuum. Depressed patients had a perceptual bias towards unpleasant versus pleasant expressions and the hypersensitivity to angry facial signals might influence the interaction behaviors between depressed patients and others.