Impact of chronic sleep restriction on sleep continuity, sleep structure, and neurobehavioral performance

The effects of insufficient sleep and adequate sleep on cognitive function in healthy adults

STUDY OBJECTIVES

Although sleep affects a range of waking behaviors, the majority of studies have focused on sleep loss with relatively little attention on sustained periods of adequate sleep. The goal of this study was to use an experimental design to examine the effect of both of these sleep patterns on cognitive performance in healthy adults.

METHODS

This study used a randomized crossover design. Participants who regularly slept 7-9 hours/night completed two 6-week intervention conditions, adequate sleep (maintenance of habitual bed/wake times) and insufficient sleep (reduction in sleep of 1.5 hours relative to adequate sleep), separated by a 2-6weeks (median=43days) washout period. Cognitive functioning was evaluated at baseline and endpoint of each intervention using the NIH Toolbox Cognition Battery. General linear models contrasted scores following each condition to the baseline of the first condition; the baseline of the second condition was included to evaluate practice effects.

RESULTS

Sixty-five participants (age 35.9 ± 4.9years, 89% women, 52% non-White race/ethnicity) completed study procedures. There was improvement in performance on the List Sorting Working Memory task after the adequate sleep condition that exceeded practice effects. Cognitive performance after insufficient sleep did not reach the level expected with practice and did not differ from baseline. A similar pattern was found on the Flanker Inhibitory Control and Attention task.

CONCLUSIONS

These findings contribute to our understanding of the complex interplay between sleep and cognition and demonstrate that consistent, stable sleep of at least 7 hours/night improves working memory and response inhibition in healthy adults.

CLINICAL TRIAL REGISTRATION

The manuscript reports on data from two clinical trials: Impact of Sleep Restriction on Performance in Adults (URL: https://clinicaltrials.gov/ct2/show/NCT02960776, ID Number: NCT02960776) and Impact of Sleep Restriction in Women (URL: https://clinicaltrials.gov/ct2/show/NCT02835261, ID Number: NCT02835261).

Self-reported sleep tendency poorly predicts the presence of obstructive sleep apnea in commercial truck drivers

BACKGROUND AND OBJECTIVES

Drowsy driving increases the risk of motor vehicle crashes in those with untreated obstructive sleep apnea (OSA). Although previous studies indicated that excessive daytime sleepiness (EDS) might not predict OSA, they were not conclusive due to their small study sizes or restricted participants to sleep clinic patients. The overall objective was to determine whether self-reported EDS can be used for case identification of OSA among commercial truck drivers.

METHODS

Commercial truck drivers (N = 19,699) were screened for OSA-related symptoms. EDS was determined using the Epworth Sleepiness Scale (ESS) ≥ 11 and all participants completed the home sleep apnea test using a type 4 portable monitor to derive the respiratory event index (REI). Regression analyses were used to characterize the association between EDS and REI.

RESULTS

EDS was associated with OSA severity (p for trend <0.001). The sensitivity and specificity values of EDS for identifying moderate-to-severe OSA (REI ≥15 events/hour) were 0.10 and 0.93, respectively, and 0.48 and 0.71 if BMI ≥25 kg/m2 was added. Those using BMI ≥25 kg/m2 with OSA-related signs yielded the best sensitivity and specificity of 0.77 and 0.50, which were not improved by the addition of EDS.

CONCLUSIONS

Despite the associations between EDS and OSA severity and between OSA and lethal crash, case-identification of OSA using the ESS in commercial truck drivers is poor. Thus, OSA screening strategy may need a special approach, including a hierarchical combination of screening tools (Swiss Cheese Model approach), and incorporation of home sleep apnea testing.

Frequency of antidepressant use and clinical characteristics of children and adolescents undergoing polysomnography: an observational study

BACKGROUND

Antidepressants are increasingly used in children for various psychiatric disorders but also for sleep disorders such as insomnia; however, it is currently unknown how many children undergoing polysomnography (PSG) are taking anti-depressants. The aims were: to determine the frequency of use of antidepressants in paediatric patients referred for PSG, to identify the most common antidepressants used, to investigate the reasons for their use, and to analyse the PSG parameters found in children taking antidepressants.

METHOD

An observational cross-sectional retrospective chart review of all children undergoing PSG at Seattle Children's Hospital from 6/14/2020 to 12/8/2022 was carried out. Clinical features (such as diagnosis, especially psychiatric), sleep disorders (such as insomnia and restless sleep), and class of antidepressant used [selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCA), or atypical antidepressants], and PSG parameters were collected for further analysis.

RESULTS

Among 3,371 patients who underwent PSG during the study, 367 children were selected who were taking one antidepressant only (154 boys and 213 girls, mean age was 13.7 ± years 3.69). A significantly decreased sleep stage N3 was found in girls, who were older than boys. Children with insomnia had longer sleep latency than children without, but more N3. There was a prolonged rapid eye movement (REM) sleep latency in children with attention-deficit/hyperactivity disorder and children with autism. REM latency was longer and REM percentage smaller in children taking SNRIs. Periodic leg movement index ≥ 5/hour was found in a higher number of children taking SSRIs or SNRIs (24.9%) than in subjects taking TCA or atypical antidepressants (13.3%) (chi-square 5.29, p = 0.013).

CONCLUSIONS

Child and adolescent psychiatrists should question about the effects on sleep (both positive and negative) after initiating therapy with antidepressant medications.