Schizophrenia symptom and functional correlates of anterior cingulate cortex activation to emotion stimuli: An fMRI investigation

Abstract

Schizophrenia is a chronic mental illness characterized by distinct positive and negative symptoms and functional impairment. The anterior cingulate cortex (ACC) is a region of the brain's limbic system that is hypoactive during emotion processing in schizophrenia. Recent evidence suggests the hypoactive ACC in schizophrenia is due to negative (and not positive) symptoms. However, this finding has not been replicated and the functional significance of this relationship remains unclear. The present study examined the association between positive and negative symptoms, ACC activation to emotional images, and functional outcome in schizophrenia. Specifically, 16 schizophrenia/schizoaffective disorder (SZ/SZAF) and 15 control (CON) participants underwent an fMRI scan while completing an emotional picture-rating task. SZ/SZAF participants also completed clinician-rated measures of positive and negative symptoms and functional abilities. SZ/SZAF participants with high negative symptoms had reduced ACC activation to pleasant images relative to those with low negative symptoms and CON, who did not differ. Furthermore, amongst all SZ/SZAF participants poorer social functioning was associated with decreased ACC activation to pleasant images. Finally, ACC activation partially mediated the relationship between negative symptoms and social dysfunction. These results provide evidence of the functional significance of the relationship between negative symptoms and ACC dysfunction in schizophrenia.