Salience network and olanzapine in schizophrenia: implications for treatment in anorexia nervosa

The salience network (SN), a set of brain regions composed of the anterior fronto-insular cortex (aFI) and the anterior cingulate cortex (ACC), is usually involved in interoception, self-regulating, and action selection. Accumulating evidence indicates that dysfunctions in this network are associated with various pathophysiological deficits in both schizophrenia and eating disorders, stemming mainly from dysfunctional information processing of internal or external stimuli. In addition, the metabolic side effects of some antipsychotics (APs), as well as their pharmacological mechanisms of action, also suggest a link between the functional and neurophysiological changes in the brain in both schizophrenia and in eating disorders. Nevertheless, there is still a knowledge gap in explicitly and directly linking the metabolic side effects associated with AP treatment with the dysfunction in SN associated with processing of food-related information in schizophrenia. Here we provide neuroimaging evidence for such a link, by presenting data on a group of schizophrenia patients who followed 16 weeks of olanzapine treatment and undertook a passive viewing task while their brain activity was recorded. In response to food-related dynamic stimuli (video clips), we observed a decreased activity in SN (aFI and ACC) after the treatment, which also correlated with ghrelin plasma concentration and a measure of dietary restraint. Taken together with past findings regarding the role of SN in both schizophrenia and eating disorders, our results suggest that enhancing the reactivity in the SN has the potential to be a treatment strategy in people with anorexia nervosa.

NCT 00290121.