1116 Interactions Among Interoceptive Sensitivity And Insomnia Symptoms In Individuals With Generalized Anxiety Disorder

Abstract Introduction Abnormal interoception is believed to contribute to anxiety disorders as well as possibly to Insomnia Disorder. We therefore hypothesized that interoceptive sensitivity in persons with Generalized Anxiety Disorder (GAD) would vary with sleep quality and would differ between GAD patients with and without insomnia. Methods 29 subjects (86% female) who reported GAD-7 scores ≥ 10 underwent psychiatric and sleep-disorders interviews and met DSM-5 criteria for GAD. Participants were assigned into an insomnia group if the Insomnia Severity Index (ISI) score exceeded 12 (N=18) or a non-insomnia group if ISI score < 11 (N=11). Participants completed approximately 2 weeks of actigraphy and sleep diaries (mean=14.09 days; SD=4.85) as well as online surveys of sleep quality including the Pittsburg Sleep Quality Index (PSQI) and interoceptive sensitivity including the Multidimensional Assessment of Interoceptive Awareness, the somatic anxiety scale of the State-Trait Inventory for Cognitive and Somatic Anxiety-Trait (STICSA-T) and the Anxiety Sensitivity Index. In addition, 28 participants underwent the Schandry heartbeat-counting task, an objective measure of interoceptive sensitivity. Results GAD-7 scores did not differ between insomnia and non-insomnia groups (t(18.36)=0.074, p = 0.941). However, insomniacs reported significantly higher scores on the somatic anxiety scale of the STICSA than non-insomniacs (t(17.71)=2.094, p=0.051). STICSA-T somatic anxiety scores positively correlated with greater PSQI scores (R=0.588; p=0.002) and trended negatively with actigraphy sleep-efficiency (R = -0.384; p=0.085). Non-insomniacs outperformed insomniacs in the Schandry task (t(25.9)=2.21, p=0.036). Higher Schandry scores were positively correlated with greater total sleep time (R=0.515; p=0.014) and lower ISI scores (R= -0.387; p=0.042). Conclusion Results suggest that GAD patients with insomnia have lesser objective interoceptive sensitivity and more subjective somatic anxiety than those without insomnia. Greater somatic anxiety predicted poorer subjective and objective sleep quality. Hence interoceptive sensitivity may vary with sleep disturbance in GAD. Support R21MH115279