Few neuroimaging studies have examined other specified schizophrenia spectrum and other psychotic disorder (OSSO). We sought to identify features differentiating patients with OSSO from those with schizophrenia spectrum disorders (SSD) and healthy controls (HC) using auditory seed-based functional connectivity (FC) analysis. Patients with OSSO (n = 88), patients with SSD (n = 81), and HC (n = 85), matched for age, sex, and education, underwent resting-state functional magnetic resonance imaging (rs-fMRI) and clinical evaluation. To reduce heterogeneity of OSSO, individuals with specific subtypes of OSSO, i.e., pure delusion and delusion with attenuated auditory hallucinations (AHs) were only included. Using five auditory seeds, we conducted seed-to-voxel and seed-to-region of interest (ROI) analyses. We also conducted between- and within-network connectivity analyses of 13 networks, and correlations of altered FC with symptomatology were explored. The SSD group showed significantly greater connectivity between the superior temporal gyrus (STG) and precuneus, and between the temporal pole cortex (TP) and precuneus, compared to the OSSO group. Overall auditory seed-based hypoconnectivity and middle temporal gyrus-based hyperconnectivity were observed in both groups compared to HC. In OSSO, hallucination severity was positively associated with insula-putamen connectivity, whereas delusional and negative symptoms showed inverse correlations with TP-insula and STG-Heschl's gyrus connectivity, respectively. In SSD, hallucination severity correlated positively with STG-Heschl's gyrus and TP-insula connectivity whereas negative symptoms correlated negatively with STG-insula connectivity. These findings suggest that there are distinct differences in FC between patients with OSSO and patients with SSD, which supports the proposal that OSSO should be treated as a separate clinical syndrome with distinct neural connectomes. Future research may explore whether interventions targeting these altered connectivity patterns could help reduce the risk of progression from OSSO to SSD.
© 2026. The Author(s).