Do Placebos Primarily Affect Subjective as Opposed to Objective Measures? A Meta-Analysis of Placebo Responses in Insomnia RCTs.

INTRODUCTION: Little is known about the relative magnitude of placebo responses on objective and subjective measures of sleep continuity. To address this issue, the pre-post effects of placebos on objective and subjective measures (i.e., polysomnography [PSG] and sleep diaries) were evaluated meta-analytically. The guiding hypothesis was that large responses would be observed on sleep diary measures and small responses would be observed on PSG measures. METHODS: PubMed searches, 1967-2016, yielded 329 possible articles, 17 of which met the inclusion and exclusion criteria for the present analysis (including 879 subjects with PSG data, 1,209 subjects with diary data, and six studies with both PSG and sleep diary data). Average change and weighted effect sizes (ESs) were computed via modeling for sleep latency (SL), wake after sleep onset (WASO) and total sleep time (TST). RESULTS: Pre-to-post change on PSG measures were: SL -13.7 min., ES = -0.37; WASO -14.3 min., ES = -0.36; and TST 29.8 min., ES = 0.50. Pre-to-post change on sleep diary measures were: SL -13.5 min., ES = -0.36; WASO -13.3 min., ES = -0.20; and TST 25.5 min., ES = 0.36. The modeled average objective subjective difference per sleep continuity measure was less than 5 minutes. The modeled average objective subjective difference per sleep continuity measure (in effect sizes) was less than 0.17. DISCUSSION: The observed outcomes of this analysis suggest that placebos produce comparable effects on objective and subjective measures of sleep continuity. Thus, objective measures do not appear to protect against placebo responses. This being the case and given the importance of the subjective experience of illness severity and recovery, such data suggests that prospectively sampled sleep continuity data (sleep diaries) may be the optimal data for clinical trials, particularly when only one measure is possible.

The natural history of insomnia: Does sleep extension differentiate between those that do and do not develop chronic insomnia?

According to the "3P model" of insomnia, the variable that mediates the transition from acute insomnia (AI) to chronic insomnia is "sleep extension" (the behavioural tendency to expand sleep opportunity to compensate for sleep loss). In the present analysis, we sought to evaluate how time in bed (TIB) varies relative to the new onset of AI and chronic insomnia. A total of 1,248 subjects were recruited as good sleepers (GS). Subjects were monitored over 1 year with sleep diaries. State transitions were defined, a priori, for AI, recovered from AI (AI-REC), and for chronic insomnia (AI-CI). Two additional groupings were added based on profiles that were unanticipated: subjects that exhibited persistent poor sleep following AI (AI-PPS [those that neither recovered or developed chronic insomnia]) and subjects that recovered from chronic insomnia (CI-REC). All the groups (GS, AI-REC, AI-CI, AI-PPS and CI-REC) were evaluated for TIB differences with longitudinal mixed effects models. Post hoc analyses for the percentage of the groups that were typed as TIB "restrictors, maintainers, and expanders" were conducted using longitudinal mixed effects models and contingency analyses. Significant differences for pre-post AI TIB were not detected for the insomnia groups. Trends were apparent for the AI-CI group, which suggested that minor increases in TIB occurred weeks before the declared onset of AI. Additionally, it was found that a significantly larger percentage of AI-CI subjects engaged in sleep extension (as compared to GS). The present data suggest that transition from AI to chronic insomnia does not appear to be initiated by sleep extension and the transition may occur before the elapse of 3 months of ≥3 nights of sleep continuity disturbance. Given these findings, it may be that the mismatch between sleep ability and sleep opportunity is perpetuated over time given the failure to "naturally" engage in sleep restriction (as opposed to sleep extension).

Insomnia Symptoms and Suicide-Related Ideation in U.S. Army Service Members.

Background: Insomnia has been identified as a key risk factor for suicide, though most studies have been limited to global measures of these constructs. The aim of the present study was to evaluate the link between insomnia symptoms and five different aspects of suicide-related ideation. Participants: 1,160 active U.S. Army service members (719 male; Mage = 31.2; SDage = 8.62). Methods: As part of an archival analysis, retrospectively assessed insomnia, depression, anxiety symptoms, as well as suicide-related ideation, were evaluated. Suicide-related ideation was assessed in terms of: thoughts of death, thoughts of suicide, suicidal plan, suicidal intent, and suicidal communication. Results: Subjects with clinically significant insomnia symptoms were 3.5 times more likely to report any suicide-related ideation, and approximately 3 times more likely to report thoughts of death and thoughts of suicide. More frequent nocturnal awakenings (i.e., waking up three or more times during a single night) were associated with a greater likelihood of reporting thoughts of death or suicide, whereas greater middle insomnia (i.e., waking up and having difficulty getting back to sleep) was associated with lower odds of experiencing thoughts of suicide, suicidal plan, and suicidal intent. Conclusions: A more refined delineation of insomnia and suicide-related ideation may serve to clarify the nature of the association, and potentially offer some clues as to the underlying mechanisms. With regard to potential clinical implications, the results support that careful assessment of insomnia symptoms, suicide-related ideation, and their respective subtypes, is important and may influence how we estimate risk for suicide.

Suicidal ideation is associated with nighttime wakefulness in a community sample.

STUDY OBJECTIVES: Nocturnal wakefulness is a risk factor for suicide and suicidal ideation in clinical populations. However, these results have not been demonstrated in general community samples or compared to sleep duration or sleep quality. The present study explored how the timing of wakefulness was associated with suicidal ideation for weekdays and weekends. METHODS: Data were collected from 888 adults aged 22-60 as part of the Sleep and Healthy Activity, Diet, Environment, and Socialization study. Suicidal ideation was measured by the Patient Health Questionnaire-9, while timing of wakefulness was estimated from the Sleep Timing Questionnaire. Binomial logistic regressions estimated the association between nocturnal (11 pm-5 am) and morning (5 am-11 am) wakefulness and suicidal ideation. RESULTS: Nocturnal wakefulness was positively associated with suicidal ideation on weekdays (OR: 1.44 [1.28-1.64] per hour awake between 11:00 pm and 05:00 am, p < 0.0001) and weekends (OR: 1.22 [1.08-1.39], p = 0.0018). Morning wakefulness was negatively associated with suicidal ideation on weekdays (OR: 0.82 [0.72-0.92] per hour awake between 05:00 am and 11:00 am, p = 0.0008) and weekends (OR: 0.84 [0.75-0.94], p = 0.0035). These associations remained significant when adjusting for sociodemographic factors. Additionally, nocturnal wakefulness on weekdays was associated with suicidal ideation when accounting for insomnia, sleep duration, sleep quality, and chronotype (OR 1.25 [1.09-1.44] per hour awake, p = 0.002). CONCLUSION: Wakefulness at night was consistently associated with suicidal ideation. Additionally, morning wakefulness was negatively associated with suicidal ideation in some models. Although these findings are drawn from a non-clinical sample, larger longitudinal studies in the general population are needed to confirm these results.

What makes people want to make changes to their sleep? Assessment of perceived risks of insufficient sleep as a predictor of intent to improve sleep.

OBJECTIVES: The objective of the present study is to identify which underlying beliefs about the impact of sleep on health may motivate change in sleep behavior. DESIGN: A cross-sectional study conducted between 2012 and 2014. SETTING: Data were from the Sleep and Healthy Activity, Diet, Environment, and Socialization (SHADES) study conducted in Philadelphia, PA, and its surrounding regions. PARTICIPANTS: Participants consisted of N = 1007 community-dwelling adults age 22-60. MEASUREMENTS: Respondents indicated behaviors they could improve on to facilitate sleep and their corresponding readiness to change. They were also asked items from the Sleep Practices and Attitudes Questionnaire (SPAQ) regarding the degree to which they agree with whether "not getting enough sleep" can impact a variety of health factors. RESULTS: In adjusted analyses, stage of change was associated with degree of agreement that insufficient sleep can cause sleepiness (odds ratio [OR] = 1.17, P = .035), weight gain (OR = 1.20, P < .0005), heart disease (OR = 1.21, P = .001), cholesterol (OR = 1.13, P = .047), hypertension (OR = 1.16, P = .014), moodiness (OR = 1.42, P < .0005), decreased energy (OR = 1.30, P = .002), absenteeism (OR = 1.13, P = .007), decreased performance (OR = 1.20, P = .003), concentration/memory problems (OR = 1.23, P = .004), diabetes (OR = 1.14, P = .042), and feeling tired (OR = 1.39, P < .0005). When sleep duration was added to the model, significant associations remained for all except cholesterol. When accounting for insomnia, significant associations were maintained for only weight, moodiness, performance, diabetes, and tiredness. CONCLUSIONS: Degree of belief that insufficient sleep can cause outcomes such as moodiness, occupational problems, and health problems may impact whether an individual is contemplating/attempting to change their sleep-related behaviors. Targeting these key messages about the associations between sleep health with moodiness and weight gain in informational material may enhance education/outreach efforts aimed at adults.

The common denominators of sleep, obesity, and psychopathology.

Sleep is an important contributor to mental and physical health. Insomnia, nightmares, and other sleep disturbances are closely linked to depression, anxiety, weight gain, diabetes, and progression of cardiometabolic disease. The high comorbidity between sleep problems, obesity, and mental illness suggest that common mechanisms are at work between them. This review discusses the presence of bivariate relations between sleep, obesity, and psychopathology, as well as the limited evidence suggesting interactions among all three. While the review identifies obstructive sleep apnea, food intake, and inflammation as potential linking mechanisms, the dearth of current literature limits strong conclusions. More data is needed to evaluate the potential moderating/mediating influences between sleep, obesity, and mental health.

Relationship of Nocturnal Wakefulness to Suicide Risk Across Months and Methods of Suicide.

OBJECTIVE: Insomnia is a risk factor for suicide, and the risk of suicide after accounting for population wakefulness is disproportionately highest at night. This study investigated whether this risk varied across months and/or methods of suicide. METHODS: Time, date, method (eg, firearm, poisoning), and demographic information for 35,338 suicides were collected from the National Violent Death Reporting System for the years 2003-2010. Time of fatal injury was grouped into 1-hour bins and compared to the estimated hourly proportion of the population awake from the American Time Use Survey for 2003-2010. Negative binomial modeling then generated hourly incidence risk ratios (IRRs) of suicide. Risks were then aggregated into 4 categories: morning (6:00 am to 11:59 am), afternoon (noon to 5:59 pm), evening (6:00 pm to 11:59 pm), and night (midnight to 5:59 am). RESULTS: The risk of suicide was higher at night across all months (P < .001) and methods (P < .001). The mean nocturnal IRR across months was 3.18 (SD = 0.314), with the highest IRR in May (3.90) and the lowest in November (2.74). The mean (SD) nocturnal IRR across methods was 3.09 (0.472), with the highest IRR for fire (3.75) and the lowest for drowning (2.44). Additionally, nocturnal risk was elevated within all demographics (all P < .001). However, there were no month-by-time or method-by-time interactions across demographics (all P > .05). CONCLUSIONS: Regardless of month or method, the incidence risk of suicide at night is higher than at any other time of day. Additionally, demographic subgroups did not differentially experience higher risks across months or mechanisms at night.

Onset insomnia and insufficient sleep duration are associated with suicide ideation in university students and athletes.

BACKGROUND: Previous work has shown that poor sleep is a prospective risk factor for suicide in clinical populations and might contribute to risk in the general population. The present study evaluated whether sleep distress, onset insomnia, and insufficient sleep are associated with suicide ideation in university students and athletes participating in the 2011-2014 National College Health Assessment (NCHA; n = 113,185). METHODS: In the NCHA survey, students self-reported the presence or absence of suicide ideation within the past 12 months. SLEEP DISTRESS was assessed with an item indicating that "sleep difficulties" were "particularly traumatic or difficult to handle." ONSET INSOMNIA was assessed as at least 3 nights per week where survey participants reported an "extremely hard time falling asleep." INSUFFICIENT SLEEP was operationalized as the number of days per week where the participants felt they did not get "enough sleep to feel rested." All variables were yes/no except INSUFFICIENT SLEEP, which was categorized as 0-1 (reference), 2-3, 4-5, or 6-7 nights. Binary logistic regression analyses examined suicide ideation as the outcome and sleep variable as a predictor, adjusted for age, sex, year in school, recent depressed mood, and survey year. Associations within student-athletes were likewise assessed. RESULTS: 7.4% of students reported suicide ideation within the past 12 months. In adjusted models, this was significantly associated with SLEEP DISTRESS (OR = 3.01, 95% CI [2.86, 3.16], p < 0.0001), ONSET INSOMNIA (OR = 1.95, 95% CI [1.86, 2.04], p < 0.0001), as well as INSUFFICIENT SLEEP (4-5 nights, OR = 1.41, 95% CI [1.28, 1.56], p < 0.0001; 6-7 nights, OR = 1.92, 95% CI [1.74, 2.13], p < 0.0001). Although suicide ideation was less common among athletes, ORs were similar for athletes for all sleep variables of interest. CONCLUSION: Sleep distress, onset insomnia, and insufficient sleep were all strongly related to suicide ideation among university students. These relationships were the same among collegiate athletes, even though this group reported less overall suicide ideation. Our findings suggest that university students may benefit from educational materials linking sleep disruption to maladaptive thinking and suicide ideation.

The Natural History of Insomnia: the incidence of acute insomnia and subsequent progression to chronic insomnia or recovery in good sleeper subjects.

STUDY OBJECTIVES: The primary aim of the present study was to estimate the incidence per annum of acute insomnia and to what extent those that develop acute insomnia recover good sleep or develop chronic insomnia. Unlike prior studies, a dense-sampling approach was used here (i.e. daily diaries) and this allowed for a more precise detection of acute insomnia and the follow-on states (the transitions to either recovery or chronic insomnia). METHODS: Good sleeper subjects (n = 1,248; 67% female) that were at least 35 years old participated in this prospective study on the natural history of insomnia. Subjects were recruited nationwide and completed online assessments for 1 year. The online measures consisted primarily of daily sleep diaries, as well as weekly/bi-weekly and monthly measures of sleep, stress, and psychological and physical health. RESULTS: The 1-year incidence rate of acute insomnia was 27.0% (n = 337). The incidence rate of chronic insomnia was 1.8% (n = 23). Of those that developed acute insomnia, 72.4% (n = 244) went on to recover good sleep. 19.3% (n = 65) of the acute insomnia sample continued to experience persistent poor sleep, but did not meet criteria for chronic insomnia. CONCLUSIONS: The incidence rate of acute insomnia (3 or more nights a week for between 2 and 12 weeks) is remarkably high. This said, most incident cases resolve within a few days to weeks. Incident chronic insomnia only occurs in about 2 in 100 individuals.