0338 Association of Evening Circadian Preference and Languid/Flexible Circadian Type with Predisposing, Perpetuating Factors, and Treatment Acceptability in Patients with Chronic Insomnia Disorder

Abstract Introduction Circadian factors may contribute to sleep difficulties among chronic insomnia disorder (CID) patients who do not otherwise meet full criteria for a circadian rhythm sleep-wake disorder, particularly delayed and advanced phase disorders. Current nosology suggests that using preference measures can provide important diagnostic information aid in differential diagnosis. However, there is lack of research identifying clinical associated with dimensions CID. Methods 195 (45.50±15.99 years old, 66.2% female, 15.9% minority) diagnosis CID absent any other were evaluated at the Behavioral Sleep Medicine (BSM) program Penn State Health Research & Treatment Center. All completed type, severity, arousability, reactivity, pre-sleep arousal, schedule incompatible behaviors, dysfunctional beliefs attitudes, mood stress, treatment acceptability. Multivariable linear regression examined which predisposing, perpetuating acceptability each dimension, while adjusting age, sex, race/ethnicity severity. Results About 30% sample was classified as evening, 29% morning, 74% languid, 43% flexible types. Sleep-wake irregularity eveningness (β=-0.276, p<0.01), languidity (β=0.280, p<0.01) flexibility (β=0.184, p<0.01). Pre-sleep cognitive arousal (β=-0.182, expectations (β=-0.127, p<0.05) eveningness. Negative cognitions about consequences (β=0.230, (β=0.268, languidity. Sleep-incompatible behaviors (β=0.165, perceived stress (β=0.267, flexibility, trait anxiety (β=-0.137, p=0.058) negative (β=-0.318, rigidity. Less agreeability pharmacotherapy over behavioral therapy morningness (β=0.129, p<0.05), greater (β=-0.158, Conclusion factor strongly evening languid/flexible types, predisposing be also determined by and/or type. evaluation help clinicians individualize BSM treatments, including patients’ Support (If Any)