Nocturnal cognitive arousal is associated with objective sleep disturbance and indicators of physiologic hyperarousal in good sleepers and individuals with insomnia disorder

BACKGROUND: Cognitive arousal is central to models of sleep disturbance and insomnia, but findings remain mixed regarding whether cognitive arousal is associated with objective sleep disturbance and physiologic hyperarousal. This study explored associations of objective nocturnal wakefulness and indicators of physiologic hyperarousal with cognitive arousal in healthy sleepers and individuals with insomnia. METHODS: In sum, 52 adults (51.9% women; 18 with insomnia disorder, 34 healthy sleepers) underwent two overnight polysomnography (PSG) studies (adaptation + baseline nights) and a multiple sleep latency test (MSLT). Baseline depression was assessed and presleep cognitive arousal and somatic arousal were recorded for each night. Multivariate regression was used to evaluate associations of PSG sleep parameters with insomnia, cognitive arousal, and somatic arousal. RESULTS: Analyses showed that high levels of nocturnal cognitive arousal were associated with prolonged sleep latency, lower sleep efficiency, and shorter total sleep time by PSG on both nights. An association between nocturnal cognitive arousal and wake after sleep onset was observed on night one only. Moreover, greater nocturnal cognitive arousal was associated with greater likelihood of obtaining short sleep and with longer MSLT sleep latencies. Insomnia diagnosis, depression, and somatic arousal were not associated with PSG sleep parameters or MSLT latency. CONCLUSIONS: Heightened cognitive arousal at night is linked to objective sleep disturbances and indicators of physiologic hyperarousal at night and during the day. For patients with insomnia, cognitive arousal may contribute to the 24-hr physiologic hyperarousal. Cognitive arousal may be a critical therapeutic target for severe or treatment-resistant sleep disturbance