Methodological approach to sleep state misperception in insomnia disorder: Comparison between multiple nights of actigraphy recordings and a single night of polysomnography recording.

STUDY OBJECTIVE: To provide a comprehensive assessment of sleep state misperception in insomnia disorder (INS) and good sleepers (GS) by comparing recordings performed for one night in-lab (PSG and night review) and during several nights at-home (actigraphy and sleep diaries). METHODS: Fifty-seven INS and 29 GS wore an actigraphy device and filled a sleep diary for two weeks at-home. They subsequently completed a PSG recording and filled a night review in-lab. Sleep perception index (subjective/objective × 100) of sleep onset latency (SOL), sleep duration (TST) and wake duration (TST) were computed and compared between methods and groups. RESULTS: GS displayed a tendency to overestimate TST and WASO but correctly perceived SOL. The degree of misperception was similar across methods within the GS group. In contrast, INS underestimated their TST and overestimated their SOL both in-lab and at-home, yet the severity of misperception of SOL was larger at-home than in-lab. Finally, INS overestimated WASO only in-lab while correctly perceiving it at-home. While only the degree of TST misperception was stable across methods in INS, misperception of SOL and WASO were dependent on the method used. CONCLUSIONS: We found that GS and INS exhibit opposite patterns and severity of sleep misperception. While the degree of misperception in GS was similar across methods, only sleep duration misperception was reliably detected by both in-lab and at-home methods in INS. Our results highlight that, when assessing sleep misperception in insomnia disorder, the environment and method of data collection should be carefully considered.

Insomnia symptoms among older adults during the first year of the COVID-19 pandemic: A longitudinal study.

OBJECTIVE: To identify sociodemographic, psychological, and health factors related to trajectories of insomnia symptoms in older adults during the COVID-19 pandemic. METHODS: From May 2020 to May 2021, 644 older adults (mean age = 78.73, SD = 5.60) completed telephone-administered self-reported measures (ie, Insomnia Severity Index, consensus sleep diaries, UCLA Loneliness Scale, Kessler Psychological Distress Scale, Post-Traumatic Checklist, perceived health threat, and International Physical Activity Questionnaire) and provided sociodemographic data at 4 timepoints. Using the Insomnia Severity Index score at each timepoint, group-based trajectory modeling was conducted to identify groups with distinct insomnia trajectories. RESULTS: On average, there was no significant change in insomnia symptoms over time. Three groups with distinct sleep trajectories were identified: clinical (11.8%), subthreshold (25.3%), and good sleepers (62.9%). Older adults who were younger, male, had elevated psychological distress and posttraumatic stress disorder symptoms, perceived more SARS-CoV-2 health threat, spent more time in bed, and had shorter sleep duration during the first wave of the pandemic were more likely to belong to the clinical than to the good sleepers group. Those who were younger, female, had elevated psychological distress and PTSD symptoms, greater loneliness, spent more time in bed, and had reduced sleep duration during the first wave were more likely to belong to the subthreshold than to the good sleepers group. CONCLUSIONS: Over 1 in 3 older adults experienced persistent subthreshold or clinically significant insomnia symptoms. Both sleep-related behaviors as well as general and COVID-19-related psychological factors were associated with insomnia trajectories.

Effects of cognitive behavioral therapy for insomnia on subjective and objective measures of sleep and cognition.

STUDY OBJECTIVES: To assess the effects of Cognitive Behavioral Therapy for insomnia (CBTi) on subjective and objective measures of sleep, sleep-state misperception and cognitive performance. METHODS: We performed a randomized-controlled trial with a treatment group and a wait-list control group to assess changes in insomnia symptoms after CBTi (8 weekly group sessions/3 months) in 62 participants with chronic insomnia. To this end, we conducted a multimodal investigation of sleep and cognition including subjective measures of sleep difficulties (Insomnia Severity Index [ISI]; sleep diaries) and cognitive functioning (Sahlgrenska Academy Self-reported Cognitive Impairment Questionnaire), objective assessments of sleep (polysomnography recording), cognition (attention and working memory tasks), and sleep-state misperception measures, collected at baseline and at 3-months post-randomization. We also assessed ISI one year after CBTi. Our main analysis investigated changes in sleep and cognition after 3 months (treatment versus wait-list). RESULTS: While insomnia severity decreased and self-reported sleep satisfaction improved after CBTi, we did not find any significant change in objective and subjective sleep measures (e.g., latency, duration). Degree of discrepancy between subjective and objective sleep (i.e., sleep misperception) in sleep latency and sleep duration decreased after CBTi suggesting a better perception of sleep after CBTi. In contrast, both objective and subjective cognitive functioning did not improve after CBTi. CONCLUSIONS: We showed that group-CBTi has a beneficial effect on variables pertaining to the subjective perception of sleep, which is a central feature of insomnia. However, we observed no effect of CBTi on measures of cognitive functioning.