Background: Psychotic-like experiences (PLEs) during childhood are associated with greater risk of developing a psychotic disorder (and other mental disorders), highlighting the importance of identifying neural correlates of childhood PLEs. Three major cortical networks-the cinguloopercular network (CON), default mode network (DMN), and fronto-parietal network (FPN)-are consistently implicated in psychosis and PLEs in adults. However, it is unclear whether variation in functional connectivity is associated with PLEs in school-aged children.Methods: Using hierarchical linear models, we examined the relationships between childhood PLEs and resting-state functional connectivity of the CON, DMN, and FPN, as well as the other networks using an a priori network parcellation, using data from 3,434 9-11-year-olds in the Adolescent Brain Cognitive Development (ABCD) study. We examined within-network, betweennetwork, and subcortical connectivity.Results: Decreased CON and DMN connectivity, as well as cingulo-parietal (CPAR) network connectivity, were associated with greater PLEs, even after accounting for family history of psychotic disorders, internalizing symptoms, and cognitive performance. Decreased DMN network connectivity was more strongly associated with increased delusional ideation, whereas decreased CON connectivity was more strongly associated with increased perceptual distortions. Increased CON-cerebellar and decreased CPAR-cerebellar connectivity were also associated with increased PLEs, and CPAR-cerebellar connectivity was more strongly associated with increased perceptual distortions. Conclusion:Consistent with hypotheses about the dimensionality of psychosis, our results provide novel evidence that neural correlates of PLEs, such as reduced functional connectivity of

Psychosis is linked to aberrant salience or to viewing neutral stimuli as self-relevant, suggesting a possible impairment in selfrelevance processing. Psychosis is also associated with increased dopamine in the dorsal striatum, especially the anterior caudate (Kegeles et al., 2010). Critically, the anterior caudate is especially connected to (a) the cortical default mode network (DMN), centrally involved in self-relevance processing, and (b) to a lesser extent, the cortical frontoparietal network (FPN; Choi, Yeo, & Buckner, 2012). However, no previous study has directly examined striatal-cortical DMN connectivity in psychosis risk. In Study 1, we examined resting-state functional connectivity in psychosis risk (n = 18) and control (n = 19) groups between (a) striatal DMN and FPN subregions and (b) cortical DMN and FPN. The psychosis risk group exhibited decreased connectivity between the striatal subregions and the cortical DMN. In contrast, the psychosis risk group exhibited intact connectivity between the striatal subregions and the cortical FPN. Additionally, recent distress was also associated with decreased striatal-cortical DMN connectivity. In Study 2, to determine whether the decreased striatal-cortical DMN connectivity was specific to psychosis risk or was related to recent distress more generally, we examined the relationship between connectivity and distress in individuals diagnosed with nonpsychotic emotional distress disorders (N = 25). In contrast to Study 1, here we found that distress was associated with evidence of increased striatal-cortical DMN connectivity. Overall, the present results suggest that decreased striatal-cortical DMN connectivity is associated with psychosis risk and could contribute to aberrant salience.

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Background Evidence suggests that both childhood trauma and perceived stress are risk factors for the development of psychosis, as well as negative symptoms such as anhedonia. Previous findings link increases in perceived stress to anhedonia in individuals at clinical high risk for psychosis (CHR) and depression; however, the role of childhood trauma in this relationship has not yet been explored, despite consistent evidence that it is associated with sensitisation to later stress. Aims To examine whether perceived stress mediates the relationship between childhood trauma and anhedonia in a group of youth at CHR as well as in controls (groups with depression and with no diagnosed mental health concerns). Method The study used multigroup mediation to examine the indirect effects of childhood trauma on anhedonia via perceived stress in CHR (n = 117) and depression groups (n = 284) and non-psychiatric controls (n = 124). Results Perceived stress mediated the relationship between childhood trauma and consummatory anhedonia regardless of group status. Perceived stress mediated the relationship between childhood trauma and anticipatory anhedonia for the CHR and depression groups, but not for non-psychiatric controls. Further, groups differed in the magnitude of this relationship, with the effects trending towards stronger for those in the CHR group. Conclusions Our findings suggest a potential transdiagnostic pathway through which childhood trauma contributes to anhedonia across severe mental illness.