Purpose of review: A relatively long history of research has shown that mood disorders are associated with abnormalities in the processing of emotional stimuli. Only the most recent studies, however, have begun to elucidate the specificity and neural basis of these abnormalities. This article reviews and discusses the results of these studies.
Recent findings: Individuals diagnosed with major depressive disorder exhibit an attentional bias toward negative emotional cues (e.g. sad faces), an attentional bias away from positive emotional cues (e.g. happy faces), and an enhanced memory for negative emotional material. Compared with healthy controls, individuals with major depressive disorder show increased neural activity in response to sad faces and diminished neural activity in response to happy faces in emotion-related brain circuits (e.g. amygdala and ventral striatum). Some of these abnormalities in the processing of emotional information persist after symptom remission and they have also been found in healthy individuals who are at heightened risk for the development of mood disorders.
Summary: The reviewed data show that major depressive disorder involves specific abnormalities in the cognitive and neural processing of emotional information and that these abnormalities may potentially contribute to the vulnerability for negative emotion and onset of depressive episodes.