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Abstract Introduction Emerging evidence in depression suggests that blood–brain barrier (BBB) breakdown and elevated inflammatory cytokines in states of persistent stress or trauma may contribute to the development of symptoms. Signal‐to‐noise ratio afforded by ultra‐high field MRI may aid in the detection of maladaptations of the glymphatic system related to BBB integrity that may not be visualized at lower field strengths. Methods We investigated the link between glymphatic neuroanatomy via perivascular spaces (PVS) and trauma experience in patients with major depressive disorder (MDD) and in healthy controls using 7‐Tesla MRI and a semi‐automated segmentation algorithm. Results After controlling for age and gender, the number of traumatic events was correlated with total PVS volume in MDD patients (r = 0.50, p = .028) and the overall population (r = 0.34, p = .024). The number of traumatic events eliciting horror was positively correlated with total PVS volume in MDD patients (r = 0.50, p = .030) and the overall population (r = 0.32, p = .023). Age correlated positively with PVS count, PVS total volume, and PVS density in all participants (r > 0.35, p

Abstract Introduction In psychiatric research, functional connectivity (FC) derived from resting‐state functional MRI (rsfMRI) is often used to investigate brain abnormalities in psychiatric disorders. This approach assumes implicitly that FC can recover reliable maps of the functional architecture of the brain and that these profiles of connectivity reflect trait differences underlying pathology. However, evidence of FC related to self‐generated thoughts (mind‐wandering) stands in contrast with these assumptions, as FC may reflect thought patterns rather than functional architecture. Methods Multi‐factor analysis (MFA) was used to investigate the reported content of self‐generated thoughts during high‐field (7T) rsfMRI in a repeated sample of 22 healthy individuals. To investigate the relationship between these experiences and FC, individual scores for each of these dimensions were compared with whole‐brain connectivity using the network‐based statistic (NBS) method. Results This analysis revealed three dimensions of thought content: self‐referential thought, negative thoughts about one's surroundings, and thoughts in the form of imagery. A network of connections within the sensorimotor cortices negatively correlated with self‐generated thoughts concerning the self was observed (p = .0081, .0486 FDR). Conclusion These results suggest a potentially confounding relationship between self‐generated thoughts and FC, and contribute to the body of research concerning the functional representation of mind‐wandering.