0387 ASV vs CPAP RCT: Changes in Racing Thoughts in Complex Insomnia Disorder

Abstract Introduction Racing thoughts, described by insomniacs as the inability to “turn off the mind,” is the single most common self-reported etiology for chronic sleep onset or maintenance insomnia. Overlapping psychological theories to explain racing thoughts include worry propensity, poor coping skills, somatized tension, stress response, inadequate emotional processing and learned behavior. An alternate theory—“Respiratory Threat Matrix Model of Chronic Insomnia” (RTMMCI)—described in 2007, posits racing thoughts as a subconscious protective mechanism to actively thwart sleep and thereby limit exposure to traumatizing, sleep-disordered breathing events. As the theory implies, “it feels safer to stay awake than attempt to sleep through the threat of a collapsing airway.” The RTMMCI, an alleged subconscious process, therefore cannot be directly tested. Nonetheless, preliminary work may track the effects of PAP on racing thoughts in complex insomnia patients. Methods We conducted an RCT comparing ASV vs CPAP (ResMed AirCurveTM) on complex insomnia patients without awareness of their underlying and previously undiagnosed sleep breathing disorder (related abstract “Changes in ISI” showed marked decrease in ISI). Racing thoughts were reported at bedtime, at night following awakenings, or both. At final follow-up, subjective change in the severity racing thoughts was measured with a 7-point scale, anchored by “much better” to “much worse” with “no change” at midpoint. Results At intake, 38 patients [ASV(n=17) and CPAP(n=21)] linked racing thoughts to insomnia. After 14 weeks of PAP use, the mean racing thought improvement score averaged “Better.” Only 8 patients (4 per mode) reported no change; and, no patients reported worsening. There was no difference in improvement between modes. ISI improvement correlated with improvement in racing thoughts (r=0.25, p=.03). Conclusion Despite high prevalence of sleep apnea in chronic insomnia patients, few treatment studies have investigated PAP effects on insomnia symptoms. The current research demonstrated a marked decrease in insomnia severity associated with a moderate decrease in racing thoughts following PAP treatment of SDB. Research must determine whether PAP therapy directly decreases racing thoughts or perhaps mediates the complex interaction among racing thoughts, anxiety, and insomnia. Support (If Any) ResMed Corp.