Loneliness is associated with different structural brain changes in schizophrenia spectrum disorders and major depression

Loneliness, distress from having fewer social contacts than desired, has been recognized as a significant public health crisis. Although a substantial body of research has established connections between loneliness and various forms of psychopathology, our understanding of the neural underpinnings of loneliness in schizophrenia spectrum disorders (SSD) and major depressive disorder (MDD) remains limited. In this study, structural magnetic resonance imaging (sMRI) data were collected from 57 SSD and 45 MDD patients as well as 41 healthy controls (HC). Loneliness was measured with the German version of the University of California, Los Angeles Loneliness Scale (UCLA-LS). We used FreeSurfer v7.2 for automated parcellation of cortical regions. SSD patients showed reduced cortical volume and thickness in fronto-parietal and temporal regions when compared to HC (p