An ecological approach to clinically assess nightmares in military service members with severe PTSD

Reduced REM and N2 sleep, and lower dream intensity predict increased mind-wandering

Mind-wandering is a mental state in which attention shifts from the present environment or current task to internally driven, self-referent mental content. Homeostatic sleep pressure seems to facilitate mind-wandering as indicated by studies observing links between increased mind-wandering and impaired sleep. Nevertheless, previous studies mostly relied on cross-sectional measurements and self-reports. We aimed to combine the accuracy of objective sleep measures with the use of self-reports in a naturalistic setting in order to examine if objective sleep parameters predict the tendency for increased mind-wandering on the following day. We used mobile sleep electroencephalographic (EEG) headbands and self-report scales over 7 consecutive nights in a group of 67 healthy participants yielding ~400 analyzable nights. Nights with more wakefulness and shorter REM and slow wave sleep were associated with poorer subjective sleep quality at the intraindividual level. Reduced REM and N2 sleep, as well as less intense dream experiences, predicted more mind-wandering the following day. Our micro-longitudinal study indicates that intraindividual fluctuations in the duration of specific sleep stages predict the perception of sleep quality as assessed in the morning, as well as the intensity of daytime mind-wandering the following hours. The combined application of sleep EEG assessments and self-reports over repeated assessments provides new insights into the subtle intraindividual, night-to-day associations between nighttime sleep and the next day's subjective experiences.

Cognitive behavioral therapy for insomnia treatment attrition in patients with weekly nightmares

STUDY OBJECTIVES

This study's objective was to evaluate the effect of nightmares (NMs) on attrition and symptom change following cognitive behavioral therapy for insomnia (CBT-I) treatment using data from a successful CBT-I randomized controlled trial delivered to participants with recent interpersonal violence exposure.

METHODS

The study randomized 110 participants (107 women; mean age: 35.5 years) to CBT-I or to an attention-control group. Participants were assessed at 3 time periods: baseline, post-CBT-I (or attention control), and at time 3 (T3) post-cognitive processing therapy received by all participants. NM reports were extracted from the Fear of Sleep Inventory. Participants with weekly NMs were compared with those with fewer than weekly NMs on outcomes including attrition, insomnia, posttraumatic stress disorder, and depression. Change in NM frequency was examined.

RESULTS

Participants with weekly NMs (55%) were significantly more likely to be lost to follow-up post-CBT-I (37%) compared with participants with infrequent NMs (15.6%) and were less likely to complete T3 (43%) than patients with less frequent NMs (62.5%). NMs were unrelated to differential treatment response in insomnia, depression, or posttraumatic stress disorder. Treatment with CBT-I was not associated with reduced NM frequency; however, change in sleep-onset latency from post-CBT-I to T3 predicted fewer NMs at T3.

CONCLUSIONS

Weekly NMs were associated with attrition but not a reduced change in insomnia symptoms following CBT-I. NM symptoms did not change as a function of CBT-I, but change in sleep-onset latency predicted lower NM frequency. CBT-I trials should screen for NMs and consider augmenting CBT-I to specifically address NMs.

CITATION

Hamilton NA, Russell JA, Youngren WA, et al. Cognitive behavioral therapy for insomnia treatment attrition in patients with weekly nightmares. J Clin Sleep Med. 2023;19(11):1913-1921.