Arbinaga, FélixLeñero Feria, AgustínSánchez Pérez, AnaDuran Andrada; Jara2026-07-092026-07-092025Arbinaga, F., Leñero-Feria, A., Sánchez-Pérez, A. & Durán-Andrada, J. (2026). Psychological inflexibility and its associations with chronotype and sleep quality in Spanish adults. Journal of Turkish Sleep Medicine, 13(1):50-54 https://doi.org/10.4274/jtsm.galenos.2025.83713 [Epub Ahead of Print]https://hdl.handle.net/10272/28679The primary objective of this study was to analyze self-reported sleep perception in relation to psychological inflexibility traits in adults. A total of 705 adults (65.2% women) participated, with a mean age of 27.21 years (standard deviation =10.67). The instruments used were the Pittsburgh Sleep Quality Index, the Composite Scale of Morningness, and the Acceptance and Action Questionnaire. Results showed that participants with high psychological inflexibility had a significantly greater risk of reporting poor sleep quality [odds ratio (OR) =2.632] and identifying with an evening chronotype (OR =2.825) than those with lower inflexibility scores. Higher inflexibility scores were positively associated with sleep disturbances, daily dysfunction due to poor sleep quality, use of sleep medication, and other sleep-related issues. Targeting behaviors associated with psychological inflexibility could help improve sleep-related outcomes.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/ChronotypeSubjective sleepSleep qualityPsychological flexibilitySleep perceptionjournal article10.4274/jtsm.galenos.2025.83713open access61 Psicología