0956 Diurnal Variation in Anxiety and Activity Is Influenced by Chronotype and Probable Anxiety-related Disorder Status

Abstract Introduction Anxiety symptoms can vary extensively within a given day. One factor that may influence these variations is chronotype. Evening chronotypes prefer to engage in activities (e.g., sleep, physical and social activity) later in the day and are more likely to suffer from anxiety-related disorders. We here wanted to determine how chronotype influences diurnal variation in anxiety symptoms and to what degree such effects are amplified in individuals with a probable anxiety-related disorder. Methods We examined the diurnal variation in anxiety symptoms and daily activities in morning and evening chronotypes with and without probable generalized anxiety disorder (GAD) and obsessive-compulsive disorder (OCD) in a community sample of adults (N=407; n=318 female, n=87 male, n=2 non-binary; Mage=32.1 ±8.9). Participants reported symptoms and activities during six diurnal sessions between ~08:00-00:00. Chronotype was measured by the reduced Morningness-Eveningness Questionnaire. Diurnal patterns of individual anxiety symptoms and activities and influence of probable GAD or OCD status and chronotype were tested by fitting generalized additive mixed effects models. Models were built with increasing complexity, including time of day, chronotype, and probable GAD/OCD and their interactions. Results Anxiety symptoms were higher in the evening and engagement in daily activities were lower in the morning in evening chronotypes (p's<.05), and these findings were most pronounced in those with probable GAD or OCD (p's<.05). Evening chronotypes with probable GAD or OCD reported worse anxiety symptoms in the evening and engaged less in daily activities in the morning and evening than their morning chronotype counterparts (p's<.05). Conclusion The highest levels of anxiety symptoms are experienced in the evening. The worst evening anxiety symptoms were reported in evening chronotypes, despite preferring this time of day. Personalized treatment approaches should consider that anxiety symptoms are typically highest in the evening and that this is particularly true in evening chronotypes with a high risk for having GAD or OCD. Support (if any) NIH T32HL149646 (RCC, KPW); SU-Region Stockholm (nr FoUI-980356, LB, JA); Rut and Arvid Wolff Memorial Foundation (nr FS-2021:0008, LB)