Sleep, mental health and physical health in new shift workers transitioning to shift work: Systematic review and meta-analysis.

This systematic review and meta-analysis (PROSPERO registration CRD42022309827) aimed to describe how shift work impacts new workers' sleep, mental health, and physical health during the transition to shift work and to consolidate information regarding predictors of shift work tolerance (SWT) during this transition period. Inclusion criteria included: new shift workers; sleep, mental health, or physical health outcomes; prospective study design with the first timepoint assessing workers within three months of starting shift work; and written in English. Searches from six databases returned 12,172 articles as of August 2023. The final sample included 48 papers. Publication quality and risk of bias was assessed using the critical appraisal skills program. Forty-five studies investigated longitudinal changes in sleep, mental health, or physical health outcomes and 29 studies investigated predictors of SWT (i.e., better sleep, mental and physical health). Sleep and mental health outcomes worsened following the onset of shift work, while physical health did not significantly change. Pre-shift work mental health, sleep, and work characteristics predicted SWT later in workers' careers. Shift work adversely impacts new workers' sleep and mental health early in their career, and interventions before beginning shift work are needed to promote better SWT.

Disruptions to sleep and circadian rhythms are associated with poorer athlete mental health in female, but not male, elite Australian Rules footballers.

Elite athletes are vulnerable to sleep and circadian disruption and associated mental health symptoms. This study aimed to investigate sex differences in sleep, circadian rhythms, and mental health, as well as the moderating role of sex in the prediction of mental health, among male professional and female semi-professional elite athletes. Participants were 87 elite Australian Rules football (ARF) athletes (43% female; mean [standard deviation] age 24.0 [4.1] years). Participants completed baseline questionnaires, 2 weeks of sleep/wake monitoring via actigraphy, and a circadian phase assessment (dim-light melatonin onset [DLMO]). Cross-sectional data were collected in training-only Australian Football League (AFL) Men's and Women's pre-season periods, with 53 providing data in two pre-seasons. Female athletes, relative to males, reported poorer mental health (a higher athlete psychological strain score), had a later mid-sleep time (by 28 min), reported a greater preference towards eveningness, and displayed a later circadian phase (by 33 min). For female athletes, lower sleep efficiency and lower sleep regularity were associated with poorer mental health. For female athletes, there were U-shaped relationships between both morningness-eveningness and phase angle (interval between sleep onset and DLMO time) and mental health. No significant relationships were found for male athletes. In summary, elite female ARF athletes reported poorer mental health, relative to males, especially when experiencing sleep or circadian disruption. Lifestyle factors associated with sex differences in ARF professionalism (scheduling, finances, supports) may contribute to these findings. Programmes to improve sleep, circadian alignment, and mental health among female semi-professional elite athletes should be strongly considered.

Insomnia is more likely to persist than remit after a time of stress and uncertainty: a longitudinal cohort study examining trajectories and predictors of insomnia symptoms.

STUDY OBJECTIVES: The study aimed to characterize insomnia symptom trajectories over 12 months during a time of stress and uncertainty, the coronavirus disease 2019 (COVID-19) pandemic. It also aimed to investigate sleep and psychological predictors of persistent insomnia symptoms. METHODS: This longitudinal cohort study comprised 2069 participants with and without insomnia symptoms during the first year of the pandemic. Participants completed online surveys investigating sleep, insomnia, and mental health at four timepoints over 12 months (April 2020-May 2021). Additional trait-level cognitive/psychological questionnaires were administered at 3 months only. RESULTS: Six distinct classes of insomnia symptoms emerged: (1) severe persistent insomnia symptoms (21.65%), (2) moderate persistent insomnia symptoms (32.62%), (3) persistent good sleep (32.82%), (4) severe insomnia symptoms at baseline but remitting over time (2.27%), (5) moderate insomnia symptoms at baseline but remitting over time (7.78%), and (6) good sleep at baseline but deteriorating into insomnia symptoms over time (2.85%). Persistent insomnia trajectories were predicted by high levels of sleep reactivity, sleep effort, pre-sleep cognitive arousal, and depressive symptoms at baseline. A combination of high sleep reactivity and sleep effort reduced the odds of insomnia remitting. Higher sleep reactivity also predicted the deterioration of good sleep into insomnia symptoms over 12 months. Lastly, intolerance of uncertainty emerged as the only trait-level cognitive/psychological predictor of insomnia trajectory classes. CONCLUSIONS: Insomnia was more likely to persist than remit over the first year of the COVID-19 pandemic. Addressing sleep reactivity and sleep effort appears critical for reducing insomnia persistence rates after times of stress and uncertainty.

The obstructive sleep apnoea endotypes are similar in elderly trauma-exposed veterans with and without diagnosed PTSD.

BACKGROUND: Approximately 60% of veterans living with posttraumatic stress disorder (PTSD) experience obstructive sleep apnoea (OSA). Why OSA is so prevalent in individuals with PTSD remains unknown, though PTSD may influence the underlying endotypes known to cause OSA. We examined whether these endotypes (upper airway collapsibility, muscle compensation, loop gain, and the arousal threshold) differ between those with comorbid OSA and PTSD relative to their counterparts with OSA-only. METHODS: Using the ventilatory flow pattern from diagnostic polysomnography, the OSA endotypes were measured in a retrospective cohort of 21 OSA patients with PTSD and 27 OSA-only patients. All participants were trauma exposed elderly male Australian Vietnam War veterans with mild-to-severe OSA (median Apnoea-Hypopnea index: 20.2 vs. 23.6 events/h). Age and BMI were similar between groups (70.7 vs. 71.7 years, and 28.4 vs. 28.4 kg/m2). RESULTS: There were no significant differences in the OSA endotype traits between PTSD + OSA and OSA-only patients for upper airway collapsibility (76.68 [71.53-83.56] vs. 78.35 [72.81-83.82] %Veupnea, median [IQR]), muscle compensation (4.27 [0.34-9.18] vs. 5.41 [1.83-7.21] %Veupnea), loop gain (0.56(0.17) vs. 0.60(0.14)), and arousal threshold (135.76 [126.59-147.54] vs. 146.95 [128.64-151.28] %Veupnea). CONCLUSION: The OSA endotypes in veterans with PTSD were similar to their trauma exposed OSA-only counterparts. PTSD appears to exert little influence on the OSA endotypes beyond the effect that age and trauma exposure may have. The aetiology of increased prevalence of OSA in PTSD remains unclear. Further work examining OSA endotypes using larger and more diverse samples is needed before robust conclusions can be made.

Sleep restriction alters the integration of multiple information sources in probabilistic decision-making.

The detrimental effects of sleep loss on overall decision-making have been well described. Due to the complex nature of decisions, there remains a need for studies to identify specific mechanisms of decision-making vulnerable to sleep loss. Bayesian perspectives of decision-making posit judgement formation during decision-making occurs via a process of integrating knowledge gleaned from past experiences (priors) with new information from current observations (likelihoods). We investigated the effects of sleep loss on the ability to integrate multiple sources of information during decision-making by reporting results from two experiments: the first implementing both sleep restriction (SR) and total sleep deprivation (TSD) protocols, and the second implementing an SR protocol. In both experiments, participants were administered the Bayes Decisions Task on which optimal performance requires the integration of Bayesian prior and likelihood information. Participants in Experiment 1 showed reduced reliance on both information sources after SR, while no significant change was observed after TSD. Participants in Experiment 2 showed reduced reliance on likelihood after SR, especially during morning testing sessions. No accuracy-related impairments resulting from SR and TSD were observed in both experiments. Our findings show SR affects decision-making through altering the way individuals integrate available sources of information. Additionally, the ability to integrate information during SR may be influenced by time of day. Broadly, our findings carry implications for working professionals who are required to make high-stakes decisions on the job, yet consistently receive insufficient sleep due to work schedule demands.

Awareness of errors is reduced by sleep loss.

The ability to detect and subsequently correct errors is important in preventing the detrimental consequences of sleep loss. The Error Related Negativity (ERN), and the error positivity (Pe) are established neural correlates of error processing. Previous work has shown sleep loss reduces ERN and Pe, indicating sleep loss impairs error-monitoring processes. However, no previous work has examined behavioral error awareness, in conjunction with EEG measures, under sleep loss conditions, and studies of sleep restriction are lacking. Using combined behavioral and EEG measures, we report two studies investigating the impact of total sleep deprivation (TSD) and sleep restriction (SR) on error awareness. Fourteen healthy participants completed the Error Awareness Task under conditions of TSD and 27 completed the same task under conditions of SR. It was found that TSD did not influence behavioral error awareness or ERN or Pe amplitude, however, SR reduced behavioral error awareness, increased the time taken to detect errors, and reduced Pe amplitude. Findings indicate individuals who are chronically sleep restricted are at risk for reduced recognition of errors. Reduced error awareness may be one factor contributing to the increased accidents and injuries seen in contexts where sleep loss is prevalent.

Defining and empirically testing a two-stage build-maintain model of cognitive behavioural therapy for insomnia.

Cognitive Behavioural Therapy for Insomnia is the front-line intervention for Insomnia Disorder. However, few studies have reported data on how CBT-I implementation evolves over the course of therapy or the time course of client response. This is due, in part, to no formal framework for defining stages of CBT-I. Here, we follow Spielman's original conceptualisation of Sleep Restriction Therapy (SRT) to report a two-stage model for defining stages of CBT-I, based on progression through the phases of SRT. Using data from a prior randomized clinical trial, we show the model helps identify patterns of treatment progression, which are in turn associated with baseline insomnia severity. The reported model is parsimonious and easy to implement and it holds potential for further examining and understanding a variety of CBT-I processes currently not fully understood, such as adherence and the optimal order of various CBT-I treatment components.

Moving forward on the road to recovery after concussion: participant experiences of interdisciplinary intervention for persisting post-concussion symptoms.

PURPOSE: Many factors contribute to persisting post-concussion symptoms (PPCSs), necessitating multi-modal treatment. Quantitative investigations have shown the potential of interdisciplinary intervention to reduce the burden of PPCSs and facilitate return to activities. There are often varied responses to intervention, warranting further investigation of potential factors underlying treatment response. This study aimed to explore participant experiences of i-RECOveR, an interdisciplinary intervention for PPCSs and its impact on symptoms, daily function, and concussion beliefs. MATERIALS AND METHOD: Semi-structured interviews were conducted 1-month post-treatment via videoconferencing with 13 individuals (61% female) with mild traumatic brain injury (Mage=39.77 years, SD = 16.27) who participated in i-RECOveR. Interview transcripts were analysed thematically. RESULTS: Three themes reflected participants' treatment journeys from concussion to life after treatment: (1) Dissatisfaction with Previous Consultations, reflected personal experiences prior to commencing treatment; (2) Perceived Active Ingredients of Intervention, reflected participant experiences of i-RECOveR; and (3) Impact of Interdisciplinary Intervention, reflected a range of positive changes after completing i-RECOveR. CONCLUSIONS: Findings highlight current gaps in the acute management of concussion and provide end-user insights into the facilitators and barriers of treatment engagement and response. Responses also highlight the potential positive impact of interdisciplinary treatments. Clinician perspectives should be explored in future research.

Access to additional training in concussion care and referral pathways may help medical practitioners manage patients after concussion.Clinicians working with individuals with persisting post-concussion symptoms should develop an understanding of the individual's perceived control over their symptoms, and work with them toward increasing autonomy and control and recognition that symptoms are often multifactorial in nature.Persisting post-concussion symptom rehabilitation may be improved by taking an interdisciplinary approach that is integrated individualised, and is specialised for concussion.Telehealth and hybrid treatment models are well tolerated by individuals with persisting post-concussion symptoms and may facilitate treatment engagement, especially for individuals with mild traumatic brain injury who report disabling symptoms made worse by travelling to in-person treatments.

Interdisciplinary rehabilitation for persisting post-concussion symptoms after mTBI: N=15 single case experimental design.

BACKGROUND: Despite clinical guidelines recommending an interdisciplinary approach to persisting post-concussion symptom (PPCS) management, evaluations of interdisciplinary interventions remain scant. OBJECTIVES: This pilot study aimed to explore the feasibility and preliminary efficacy of an interdisciplinary intervention for PPCSs. METHOD: A single-case experimental design with randomisation to multiple baselines (2, 4, or 6 weeks) was repeated across 15 participants (53% female) with mild traumatic brain injury (mean age 38.3 years, SD 15.7). The 12-week treatment incorporated psychology, physiotherapy, and medical interventions. Feasibility outcomes included recruitment and retention rates, adverse events, treatment adherence and fidelity. Patient-centred secondary outcomes included the Rivermead Post-Concussion Symptoms Questionnaire (RPQ), assessed 3 times per week during the baseline and treatment phases, and at the 1- and 3-month follow-ups. Other secondary outcomes included measures of mood, sleep and fatigue, physical functioning, health-related quality of life, illness perceptions, and goal attainment. Changes in PPCSs were evaluated using systematic visual analysis and Tau-U. Clinically significant changes in secondary outcomes were explored descriptively. RESULTS: 16/26 individuals assessed for eligibility were enroled (61% recruitment rate); 15 completed the post-treatment follow-ups, and 13 completed the 1- and 3-month follow-up assessments (81% retention rate). High treatment adherence and competence in delivering treatments was observed. Moderate-large effect sizes for reducing PPCSs were observed in 12/15 cases, with 7/15 reaching statistical significance. Improvements were maintained at the 1- and 3-month follow-ups and were accompanied by reductions in fatigue, sleep difficulties, and mood symptoms, and changes in illness perceptions. All participants had clinically significant improvements in at least 1 outcome, with 81% of individual therapy goals achieved. CONCLUSIONS: This pilot study provided preliminary support for a subsequent randomised controlled trial (RCT), with satisfactory recruitment, retention, treatment compliance, and treatment fidelity. Improvement was evident on participant outcomes including symptom reduction and goal attainment, suggesting that progressing to a phase-II RCT is worthwhile. Findings highlight the potential benefit of individualized interdisciplinary treatments.

Protocol for a randomized controlled study examining the role of rapid eye movement sleep in fear-related mechanisms: rapid eye movement fragmentation and fear inhibition in adults with insomnia disorders before and after cognitive behavioral therapy for insomnia.

Insomnia confers a 2.5-to-3-fold risk of developing posttraumatic stress disorder (PTSD) after a traumatic event. The mechanism underlying this increased risk, however, remains unknown. We postulate insomnia may contribute to PTSD by disrupting rapid eye movement (REM) sleep, as REM sleep disruption has been shown to impair fear inhibitory processes, which are central to the natural recovery from trauma. To test this hypothesis, the following protocol aims to: (1) examine the relationship between REM sleep and fear inhibition in insomnia, and (2) examine whether reducing REM fragmentation by treating insomnia, in turn, improves fear inhibition. Ninety-two adults with Insomnia Disorder will be block randomized (1:1; stratified by sex) to an active treatment (7 weekly sessions of Cognitive Behavioral Therapy for Insomnia (CBT-I) via telehealth) or waitlist control condition. REM sleep (latent variable derived from REM %, REM efficiency, and REM latency) and fear inhibition (i.e. safety signal and extinction recall) will be assessed pre- and post-treatment in a 4 night/3 day testing protocol via at-home polysomnography and the fear-potentiated startle paradigm, respectively. Fear extinction recall will serve as the primary outcome, while safety signal recall will serve as the secondary outcome. In summary, this study aims to test an underlying mechanism potentially explaining why insomnia greatly increases PTSD risk, while demonstrating an existing clinical intervention (CBT-I) can be used to improve this mechanism. Findings will have potential clinical implications for novel approaches in the prevention, early intervention, and treatment of PTSD.

Tailoring cognitive behavioural therapy for insomnia across contexts, conditions, and individuals: What do we know, where do we go?

Cognitive behavioural therapy for insomnia (CBT-I) is considered the front-line treatment for insomnia. Despite the demonstrated effectiveness of CBT-I, it is necessary to consider how CBT-I may be tailored to different individuals. The purpose of the present review is to provide a summary of literature on tailoring CBT-I to different individuals and provide directions for future research. This review focused on the following domains of adaptation: (i) tailoring CBT-I components to individuals with comorbid mental or physical health conditions such as comorbid depression and pain; (ii) adapting CBT-I delivery for different contexts in which individuals exist, such as inpatient, educational, and different social/cultural settings, (iii) adapting CBT-I to specific individuals via case-formulation in clinical settings. We highlight current gaps in the exploration of tailored CBT-I, including a lack of research methodology to evaluate tailored interventions, a need for the integration of ongoing individualised assessment to inform treatment, and the necessary involvement of consumers and stakeholders throughout the research and treatment development process. Together, this review showed abundant adaptations in CBT-I already exist in the literature. Future research is needed in understanding when and how to apply adaptations in CBT-I and evaluate the benefits of these adaptations.

Beta spectral power during sleep is associated with impaired recall of extinguished fear.

The failure to retain memory for extinguished fear plays a major role in the maintenance of posttraumatic stress disorder (PTSD), with successful extinction recall necessary for symptom reduction. Disturbed sleep, a hallmark symptom of PTSD, impairs fear extinction recall. However, our understanding of the electrophysiological mechanisms underpinning sleep's role in extinction retention remains underdetermined. We examined the relationship between the microarchitecture of sleep and extinction recall in healthy humans (n = 71, both male and females included) and a pilot study in individuals with PTSD (n = 12). Participants underwent a fear conditioning and extinction protocol over 2 days, with sleep recording occurring between conditioning and extinction. Twenty-four hours after extinction learning, participants underwent extinction recall. Power spectral density (PSD) was computed for pre- and post-extinction learning sleep. Increased beta-band PSD (~17-26 Hz) during pre-extinction learning sleep was associated with worse extinction recall in healthy participants (r = 0.41, p = .004). Beta PSD was highly stable across three nights of sleep (intraclass correlation coefficients > 0.92). Results suggest beta-band PSD is specifically implicated in difficulties recalling extinguished fear.

Obstructive Sleep Apnea Is a Distinct Physiological Endotype in Individuals with Comorbid Insomnia and Sleep Apnea.

Rationale: With up to 40% of individuals with either insomnia or obstructive sleep apnea (OSA) demonstrating clinically significant symptoms of the other disorder, the high degree of comorbidity among the two most common sleep disorders suggests a bidirectional relationship and/or shared underpinnings. Although the presence of insomnia disorder is believed to influence the underlying pathophysiology of OSA, this influence is yet to be examined directly. Objectives: To investigate whether the four OSA endotypes (upper airway collapsibility, muscle compensation, loop gain, and the arousal threshold) are different in patients with OSA with and without comorbid insomnia disorder. Methods: Using the ventilatory flow pattern captured from routine polysomnography, the four OSA endotypes were measured in 34 patients with OSA who met the diagnostic criteria for insomnia disorder (COMISA) and 34 patients with OSA without insomnia (OSA only). Patients demonstrated mild-to-severe OSA (apnea-hypopnea index, 25.8 ± 2.0 events/h) and were individually matched according to age (50.2 ± 1.5 yr), sex (42 male: 26 female), and body mass index (29.3 ± 0.6 kg/m2). Results: Compared with patients with OSA without comorbid insomnia, patients with COMISA demonstrated significantly lower respiratory arousal thresholds (128.9 [118.1 to 137.1] vs. 147.7 [132.3 to 165.0] % eupneic ventilation ([Formula: see text]); U = 261; 95% confidence interval [CI], -38.3 to -13.9; d = 1.1; P < 0.001), less collapsible upper airways (88.2 [85.5 to 94.6] vs. 72.9 [64.7 to 79.2] %[Formula: see text]; U = 1081; 95% CI, 14.0 to 26.7; d = 2.3; P < 0.001), and more stable ventilatory control (i.e., lower loop gain: 0.51 [0.44 to 0.56] vs. 0.58 [0.49 to 0.70]; U = 402; 95% CI, -0.2 to -0.01; d = 0.05; P = 0.03). Muscle compensation was similar between groups. Moderated linear regression revealed that the arousal threshold moderated the relationship between collapsibility and OSA severity in patients with COMISA but not in patients with OSA only. Conclusions: A low arousal threshold is an overrepresented endotypic trait in individuals with COMISA and may exhibit a greater relative contribution to OSA pathogenesis in these patients. Contrastingly, the prevalence of a highly collapsible upper airway in COMISA was low, suggesting that anatomical predisposition may contribute less to OSA development in COMISA. Based on our findings, we theorize that conditioned hyperarousal perpetuating insomnia may translate to a reduced arousal threshold to respiratory events, thereby increasing the risk or severity of OSA. Therapies that target increased nocturnal hyperarousal (e.g., through cognitive behavior therapy for insomnia) may be effective in individuals with COMISA. Clinical trial registered with the Australian and New Zealand Clinical Trial Registry (ACTRN12616000586415).

Effects of total sleep deprivation on sensorimotor gating in humans.

Sensorimotor gating is a measure of pre-attentional information processing and can be measured by prepulse inhibition (PPI) of the startle reflex. Sleep deprivation has been shown to disrupt PPI in animals and humans, and has been proposed as an early phase 2 model to probe antipsychotic efficacy in heathy humans. To further investigate the reliability and efficacy of sleep deprivation to produce PPI deficits we tested the effects of total sleep deprivation (TSD) on PPI in healthy controls in a highly controlled sleep laboratory environment. Participants spent 4 days and nights in a controlled laboratory environment with their sleep monitored with polysomnography. Participants were randomly assigned to either normal sleep on all 4 nights (N = 17) or 36 h of TSD on the 3rd or 4th night (N = 40). Participants were assessed for sleepiness using the Karolinska Sleepiness Scale (KSS) and underwent a daily PPI task (interstimlulus intervals 30-2000 ms) in the evening. Both within-subject effects (TSD vs. normal sleep in TSD group alone) and between-subject effects (TSD vs. no TSD group) of TSD on PPI were assessed. TSD increased subjective sleepiness measured with the KSS, but did not significantly alter overall startle, habituation or PPI. Sleep measures including duration, rapid eye movement and slow wave sleep duration were also not associated with PPI performance. The current results show that human sensorimotor gating may not be reliably sensitive to sleep deprivation. Further research is required for TSD to be considered a dependable model of PPI disruption for drug discovery in humans.

Cognitive fitness modulates gender differences in sleep and mental health among competitive athletes under chronic stress.

Objectives: Mental fitness is increasingly considered a key component of an athlete's competitive arsenal. Active domains of mental fitness include cognitive fitness, sleep, and mental health; and these domains can differ between men and women athletes. Our study investigated the associations of cognitive fitness and gender to sleep and mental health, and the interaction between cognitive fitness and gender on sleep and mental health, in competitive athletes during the COVID-19 pandemic. Methods: 82 athletes competing at levels from regional/state to international (49% women, M-age = 23.3 years) completed measures of self-control, intolerance of uncertainty, and impulsivity (together representing constructs of cognitive fitness), items about sleep (total sleep time, sleep latency, and mid-sleep time on free days) and a measure of mental health (depression, anxiety, and stress). Results: Women athletes reported lower self-control, higher intolerance of uncertainty, and higher positive urgency impulsivity compared with men athletes. Women reported sleeping later, but this gender difference disappeared after controlling for cognitive fitness. Women athletes-after controlling for cognitive fitness-reported higher depression, anxiety, and stress. Across genders, higher self-control was associated with lower depression, and lower intolerance of uncertainty was associated with lower anxiety. Higher sensation seeking was associated with lower depression and stress, and higher premeditation was associated with greater total sleep time and anxiety. Higher perseverance was associated with higher depression for men-but not women-athletes. Conclusion: Women athletes in our sample reported poorer cognitive fitness and mental health compared to men athletes. Most cognitive fitness factors protected competitive athletes under chronic stress, but some exposed them to poorer mental health. Future work should examine the sources of gender differences. Our findings suggest a need to develop tailored interventions aimed at improving athlete wellbeing, with a particular focus on women athletes.

Sleep and mental health in recruit paramedics: a 6-month longitudinal study.

STUDY OBJECTIVES: To explore potential relationships and longitudinal changes in sleep and mental health in recruit paramedics over the first 6 months of work, and whether sleep disturbances pre-emergency work predict future mental health outcomes. METHODS: Participants (N = 101, 52% female, Mage = 26 years) completed questionnaires prior to (baseline), and after 6 months of emergency work to assess for symptoms of insomnia, obstructive sleep apnea, post-traumatic stress disorder (PTSD), depression, anxiety, and trauma exposure. At each timepoint, participants also completed a sleep diary and wore an actigraph for 14 days to assess sleep patterns. Correlations between baseline sleep and mental health were conducted and changes in these variables across timepoints were examined using linear mixed models. Hierarchical regressions assessed whether sleep at baseline predicted mental health at follow-up. RESULTS: Insomnia and depression symptoms, and total sleep time increased while sleep onset latency decreased across the first 6 months of emergency work. Participants experienced an average of 1 potentially traumatic event during the 6-month period. Baseline insomnia predicted increased depression symptoms at the 6-month follow-up, while baseline wake after sleep onset predicted follow-up PTSD symptoms. CONCLUSION: Results highlight an increase in insomnia and depression across the initial months of emergency work, while sleep disturbances before emergency work were identified as potential risk factors for the development of depression and PTSD among paramedics in their early career. Screening and early interventions targeting poor sleep at the beginning of emergency employment may assist in reducing the risk of future mental health outcomes in this high-risk occupation.

Improving perinatal sleep via a scalable cognitive behavioural intervention: findings from a randomised controlled trial from pregnancy to 2 years postpartum.

BACKGROUND: Sleep disturbance is common in gestational parents during pregnancy and postpartum periods. This study evaluated the feasibility and efficacy of a scalable cognitive behavioural therapy (CBT) sleep intervention tailored for these periods. METHODS: This is a two-arm, parallel-group, single-blind, superiority randomised controlled trial. Nulliparous females without severe medical/psychiatric conditions were randomised 1:1 to CBT or attention- and time-matched control. All participants received a 1 h telephone session and automated multimedia emails from the third trimester until 6 months postpartum. Outcomes were assessed with validated instruments at gestation weeks 30 (baseline) and 35 (pregnancy endpoint), and postpartum months 1.5, 3, 6 (postpartum endpoint), 12 and 24. RESULTS: In total, 163 eligible participants (age M ± s.d. = 33.35 ± 3.42) were randomised. The CBT intervention was well accepted, with no reported adverse effect. Intention-to-treat analyses showed that compared to control, receiving CBT was associated with lower insomnia severity and sleep disturbance (two primary outcomes), and lower sleep-related impairment at the pregnancy endpoint (p values ⩽ 0.001), as well as at 24 months postpartum (p ranges 0.012-0.052). Group differences across the first postpartum year were non-significant. Participants with elevated insomnia symptoms at baseline benefitted substantially more from CBT (v. control), including having significantly lower insomnia symptoms throughout the first postpartum year. Group differences in symptoms of depression or anxiety were non-significant. CONCLUSIONS: A scalable CBT sleep intervention is efficacious in buffering against sleep disturbance during pregnancy and benefitted sleep at 2-year postpartum, especially for individuals with insomnia symptoms during pregnancy. The intervention holds promise for implementation into routine perinatal care.

The Influence of Transdiagnostic Vulnerability Factors on PTSD Symptom Clusters in a Veteran Sample.

BACKGROUND: There is continuing debate as to the latent structure underpinning posttraumatic stress disorder symptomatology. The transdiagnostic vulnerability factors of negative affect, anxiety sensitivity (and subcomponents) and intolerance of uncertainty have previously demonstrated the ability to explain symptom clusters in a range of anxiety and depressive disorders, and may give further understanding of PTSD symptomatology. METHOD: Within an Australian Defence Force veteran population, structural equation modeling is utilized to assess whether a hierarchical Original Model containing negative affect as the general cognitive factor, anxiety sensitivity and intolerance of uncertainty as mid-level factors, can explain variability among posttraumatic stress disorder symptom clusters as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. A further hierarchical Anxiety Sensitivity Extended model consisting of the general cognitive factor of negative affect and the three sub-factors of anxiety sensitivity as mid-level factors was also tested upon PTSD symptom clusters. RESULTS: Both the hierarchical Original and Anxiety Sensitivity Extended models fit the data well. Within both models, negative affect consistently showed significant direct effects upon the posttraumatic stress disorder symptom clusters. In the Original Model, anxiety sensitivity served as a significant mediator of negative affect for several symptom clusters, while intolerance of uncertainty was non-significant both as a direct effect and as a mediator of negative affect. In the Anxiety Sensitivity Extended Model, the cognitive concerns sub-factor of anxiety sensitivity served as a significant mediator of negative affect for several symptom clusters, while the social and physical concerns sub-factors did not have significant direct or mediating effects. CONCLUSIONS: This study demonstrates a transdiagnostic hierarchical model significantly explains the severity of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition posttraumatic stress disorder symptom constructs within a subclinical population. Negative affect and anxiety sensitivity can each be targeted with specific interventions, suggesting new avenues to augment current gold standard psychotherapeutic interventions.

The relationship between sleep and appetitive conditioning: A systematic review and meta-analysis.

This systematic review and meta-analysis (PROSPERO registration animal/human studies: CRD42021234793/CRD42021234790) examined the relationship between sleep and appetitive conditioning. Inclusion criteria included: a) appetitive conditioning paradigm; b) measure of conditioning; c) sleep measurement and/or sleep loss; d) human and/etor non-human animal samples; and e) written in English. Searches of seven databases returned 3777 publications. The final sample consisted of 42 studies using primarily animal samples and involving food- and drug-related conditioning tasks. We found sleep loss disrupted appetitive conditioning of food rewards (p < 0.001) but potentiated appetitive conditioning of drug rewards (p < 0.001). Furthermore, sleep loss negatively impacted extinction learning irrespective of the reward type. Post-learning sleep was associated with increases in REM sleep (p = 0.02). Findings suggest sleep loss potentiates the impact of psychoactive substances in a manner likely to produce an increased risk of problematic substance use. In obese/overweight populations, sleep loss may be associated with deficits in the conditioning and extinction of reward-related behaviours. Further research should assess the relationship between sleep and appetitive conditioning in humans.

Mental health risk factors for shift work disorder in paramedics: A longitudinal study.

OBJECTIVES: Depression and anxiety are prominent in paramedics, as is the prevalence of shift work disorder (SWD), a circadian sleep condition comorbid with mental health disorders. However, the role of mental health risk factors for SWD is largely unknown. This study investigated whether mental health levels in recruit paramedics before shift work predicted greater risk of SWD at 6-months into their career and explored whether shift and sleep factors mediated this relationship. DESIGN: A longitudinal study. SETTING: Victoria, Australia. PARTICIPANTS: Recruit paramedics were assessed at baseline (n = 101; ie, pre-shift work) and after 6-months (n = 93) of shift and emergency work. MEASUREMENTS: At both time points, participants completed self-reported measures of depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder Questionnaire-7), and SWD (SWD-Screening Questionnaire). Participants also filled a sleep and work diary for 14-days at each timepoint. RESULTS: After 6-months of emergency work 21.5% of paramedics had a high SWD risk. Logistic regression models showed baseline depression predicted 1.24-times greater odds for SWD at 6-months. Through Lavaan path analysis we found shift and sleep variables did not mediate the relationship between baseline mental health and SWD risk. Baseline depression was associated with increased sleepiness levels following paramedics' major sleep periods at 6-months. Pre-existing depression levels also predicted greater perceived nightshift workload. CONCLUSIONS: Our results highlight depression symptoms before emergency work are a risk factor for SWD within 6-months of work. Depression represents a modifiable risk factor amenable to early interventions to reduce paramedics' risk of SWD.