Recognition of facial expressions of emotion in euthymic patients with bipolar disorder

In this study, participants (i.e., 34 euthymic patients with bipolar disorder and 26 healthy controls) completed a computer-administered task, which measured the threshold of facial affect recognition. For the task, the participants viewed facial expressions of emotion (i.e., anger, disgust, happiness, sadness, fear, surprise, and neutral) obscured with static, that cleared up incrementally over a 17 sec time interval. Participants pushed a button when they thought they recognized the emotional expressions and earned points based upon their ability to recognize the expressions quickly (and correctly). Those participants responding correctly to more obscured expressions (i.e., more static) earned more points compared to participants responding correctly to less obscured expressions (i.e., less static). Participants then matched the emotional expressions of the images to one of seven key faces of emotion (i.e., non-verbal matching) and to one of seven labels of emotion (i.e., verbal labeling). For non-verbal matching, the comparisons between the patients and the controls did not achieve statistical significance. For verbal labeling, patients made significantly fewer correct matches for anger and significantly more correct matches for fear, compared with the healthy controls. The patients were significantly less sensitive (i.e., had a higher threshold) to happy faces, compared with the healthy controls. Threshold (or sensitivity) of recognition for facial expressions may serve as a sensitive marker of bipolar disorder during asymptomatic periods and may have a meaningful effect on the social functioning of the patients.