Chronic psychosocial stressors are associated with alterations in salience processing and corticostriatal connectivity.

Abstract

Psychosocial stressors including childhood adversity, migration, and living in an urban environment, have been associated with several psychiatric disorders, including psychotic disorders. The neural and psychological mech- anisms mediating this relationship remain unclear. In parallel, alterations in corticostriatal connectivity and ab- normalities in the processing of salience, are seen in psychotic disorders. Aberrant functioning of these mechanisms secondary to chronic stress exposure, could help explain how common environmental exposures are associated with a diverse range of symptoms. In the current study, we recruited two groups of adults, one with a high degree of exposure to chronic psychosocial stressors (the exposed group, n = 20), and one with min-imal exposure(theunexposedgroup,n = 22). Allparticipants underwenta resting state MRI scan,completedthe Aberrant Salience Inventory, and performed a behavioural task the Salience Attribution Test (SAT). The exposed group showed reduced explicit adaptive salience scores (cohen's d = 0.69, p = 0.03) and increased aberrant sa- lience inventory scores (d = 0.65, p = 0.04). The exposed group also showed increased corticostriatal connectiv- ity between the ventral striatum and brain regions previously implicated in salience processing. Corticostriatal connectivity in these regions negatively correlated with SAT explicit adaptive salience (r=−0.48, p = 0.001),and positively correlated with aberrant salience inventory scores (r= 0.42, p = 0.006). Furthermore, in a medi-ation analysis there was tentative evidence that differences in striato-cortical connectivity mediated the groupdifferences in salience scores.