Anxiety And Sleep In Generalized Anxiety Disorder With And Without Insomnia Disorder

Abstract Introduction Insomnia Disorder (ID) elevates risk of incident anxiety disorders and vice versa. We examined whether ID and poor sleep are associated with greater self-reported anxiety in persons with Generalized Anxiety Disorder (GAD). Methods Twenty-one participants with GAD and ID (GAD+/ID+) having Insomnia Severity Index (ISI) scores ≥ 13 (mean 17.8, SD 3.6) and 14 with GAD but not ID (GAD+/ID-) having ISI scores ≤ 12 (mean 6.4, SD 3.4) completed 14 days of actigraphy and sleep diaries as well as a night of ambulatory polysomnography (PSG) following an acclimation night. Participants completed the Pittsburgh Sleep Quality Index (PSQI), the State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA-T/C, -T/S), the Ford Insomnia Response to Stress Test (FIRST), the Penn State Worry Questionnaire (PSWQ), and the Anxiety Sensitivity Index (ASI). Differences in self-reported anxiety (STICSA, ASI, PSWQ) between GAD+/ID+ and GAD+/ID- were analyzed using t-tests. Relationships of anxiety with retrospective (PSQI, FIRST, ISI), longitudinal (actigraphy, diaries) and physiological (PSG) sleep variables were analyzed using simple regression. Results GAD+/ID+ versus GAD+/ID- participants showed trends toward higher anxiety on the PSWQ (p=0.075), ASI (p=0.072) and STICSA-T/S (p=0.078). PSQI scores were positively associated with STICSA-T/S, (R=0.417, p=0.018, N=32). Greater insomnia reactivity (FIRST) was associated with increased worry on the PSWQ (R=0.352, p=0.044, N=33). STICSA-T/C was negatively associated with mean diary (R= -0.440, p=0.015, N=30) and actigraph (R= -0.517, p=0.01, N=24) total sleep time (TST). Actigraph mean TST trended toward lower PSWQ (R= -0.376, p=0.058, N=26) while actigraph mean sleep efficiency (SE) trended toward lesser STICSA-T/C (R= -0.397, p=0.058). Greater REM% was associated with greater STICSA-T/C (R=0.613, p=0.0005, N=28) and STICSA-T/S (R=0.516, p=0.005), a relationship also seen in GAD+/ID+ alone (p=0.03 and 0.015 respectively, N=16). Slow Wave Sleep% (SWS%) was not associated with lesser STICSA-T/S across both groups (p=0.14) but was so in GAD+/ID+ (R= -0.539, p=0.031, N=16). Conclusion GAD+/ID+ versus GAD+/ID-, show greater worry, anxiety sensitivity and somatic anxiety. In GAD, shorter and poorer quality sleep measured retrospectively or averaged longitudinally, as well as greater REM%, are associated with greater somatic and cognitive anxiety. Among those with ID, greater SWS% is associated with less somatic anxiety. Support (if any) R21MH115279, R01MH109638