AUTHOR=Yesilkaya Umit Haluk , Chen Xi , Watford Lauren , McCoy Emma , Sen Meltem , Genc Ilgin , Du Fei , Ongur Dost , Yuksel Cagri TITLE=Poor self-reported sleep is associated with prolonged white matter T2 relaxation in psychotic disorders JOURNAL=Frontiers in Psychiatry VOLUME=Volume 15 - 2024 YEAR=2025 URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2024.1456435 DOI=10.3389/fpsyt.2024.1456435 ISSN=1664-0640 ABSTRACT=BackgroundPsychotic disorders are characterized by white matter (WM) abnormalities; however, their relationship with the various aspects of illness presentation remains unclear. Sleep disturbances are common in psychosis, and emerging evidence suggests that sleep plays a critical role in WM physiology. Therefore, it is plausible that sleep disturbances are associated with impaired WM integrity in these disorders. To test this hypothesis, we examined the association of self-reported sleep disturbances with WM transverse (T2) relaxation times in a cross-diagnostic sample of patients with psychosis.MethodsA total of 28 patients with psychosis (11 schizophrenia spectrum disorders and 17 bipolar disorder with psychotic features) were included. Metabolite (N-acetyl aspartate, choline, and creatine) and water T2 relaxation times were measured in the anterior corona radiata at 4T. Sleep was evaluated using the Pittsburgh Sleep Quality Index (PSQI).ResultsPSQI total score showed a moderate to strong positive correlation with water T2 (r = 0.64, p< 0.001). Linear regressions showed that this association was independent of the overall severity of depressive, manic, or psychotic symptoms. In our exploratory analysis, sleep disturbance was correlated with free water percentage, suggesting that increased extracellular water may be a mechanism underlying the association of disturbed sleep and prolonged water T2 relaxation.ConclusionOur results highlight the connection between poor sleep and WM abnormalities in psychotic disorders. Future research using objective sleep measures and neuroimaging techniques suitable to probe free water is needed to further our insight into this relationship.