Stimulus control (SC) is commonly viewed as an evidence-based treatment for insomnia, but it has not been evaluated comprehensively with modern review and meta-analytic techniques. The aim of the current study was thus to perform a systematic review and meta-analysis of trials that examine the efficacy of stimulus control for insomnia. A systematic search for eligible articles and dissertations was conducted in six online bibliographic databases. The 11 included studies, with the majority published between 1978 and 1998, were randomised controlled and experimental studies in adults, comparing stimulus control for insomnia with passive and active comparators and assessing insomnia symptoms as outcomes. A random effects model was used to determine the standardised mean difference Hedge's g at post-treatment and follow-up for three sleep diary measures: the number of awakenings, sleep onset latency, and total sleep time. A test for heterogeneity was conducted, forest plots were produced, the risk of publication bias was estimated, and the study quality was assessed. In the trials identified, stimulus control resulted in small to large improvements on sleep onset latency and total sleep time, relative to passive comparators (g = 0.38-0.85). Compared with active comparators, the improvements following stimulus control were negligible (g = 0.06-0.30). Although methodological uncertainties were observed in the included trials, stimulus control appears to be an efficacious treatment for insomnia when compared with passive comparators and with similar effects to active comparators. More robust studies are, however, warranted before stronger conclusions are possible to infer.

Introduction: The study aimed to explore characteristics of responders to a sleep robot intervention for adults with insomnia, and the likelihood that participants responded to the intervention. Methods: Data from the intervention and the control group in a randomized waitlist-controlled trial (n = 44) were pooled together after both had undergone the intervention. A repeated measures ANOVA and Friedman tests were used to explore changes over time. Differences in baseline characteristics between responders (n = 13), defined as a reduction of -5 on the Insomnia Severity Index from pre- to post-intervention, and non-responders (n = 31) were analyzed with t-tests and chi-square tests. Finally, logistic regression models were estimated.Results: Baseline anxiety was the only statistically significant difference between responders and non-responders (p = 0.03). A logistic regression model with anxiety and sleep quality as predictors was statistically significant, correctly classifying 83.3% of cases. Discussion: The results imply that people with lower anxiety and higher sleep quality at baseline are more likely to report clinically significant improvements in insomnia from the sleep robot intervention.

The impact factor is used to rank the quality of scientific journals but has been criticised for a number of reasons. The aim of the study was to investigate sleep researchers' perceptions of sleep journals to determine whether subjective rankings of journals were in line with the journals' impact factors. Clarivate's Journal Citation Reports website was used to identify journals containing the words 'sleep' or 'dream' in the titles with an impact factor since 2018, resulting in 12 journals. A survey including questions about how the respondent would rank these journals (e.g., three most prestigious journals) was developed. A total of 122 sleep researchers completed the survey. Sleep, Sleep Medicine Reviews and Journal of Sleep Research were ranked as the three most prestigious sleep journals, in line with the impact factors of the journals. For the rest of the journals, the subjective rankings and impact factors did not correspond as much.

IntroductionRepetitive negative thinking (RNT) has been described as a maintaining transdiagnostic factor for psychopathology within the areas of depression, anxiety and insomnia. We investigated the effects of rumination-focused cognitive-behaviour therapy (RF-CBT) in a group format at a primary health care centre on symptoms of depression, anxiety, insomnia, RNT, and quality of life. The participants presented clinical symptom levels of worry and at least two disorders among anxiety disorders, major depressive disorder, and insomnia disorder.MethodsA randomised controlled superiority parallel arm trial was used. 73 participants were included and randomised in pairs to either group-administered RF-CBT or a waiting list condition. The primary outcomes were self-rated worry and transdiagnostic symptoms (depression, anxiety, and insomnia). Intention-to-treat analyses of group differences were conducted using linear mixed models. Adverse side effects and incidents were presented descriptively.ResultsGroup RF-CBT significantly reduced self-reported insomnia at post-treatment and self-reported insomnia and depression at the 2 month-follow-up, relative to the wait-list control group. There was no significant difference in change in RNT, anxiety, or quality of life.DiscussionThe current study suggests that group-administered RF-CBT may be effective for insomnia and potentially effective for depression symptomatology. However, the study was underpowered to detect small and moderate effects and the results should therefore be interpreted with caution.

Objectives: Flotation-REST is a treatment for deep relaxation, where a person is contained in a stimuli-restricted environment and floats in water with high salt content. The aim was to investigate the effects from flotation-REST on people with insomnia diagnosis, as previous studies of flotation-REST have demonstrated some effects on sleep but have limitations regarding sample selections and sleep measures. Material and Methods: Six participants were recruited through an outpatient psychiatry clinic and posters on a university campus. All participants fulfilled criteria for insomnia diagnosis and four fulfilled criteria for major depressive disorder. Using a single case experimental design, daily changes were investigated on sleep logs regarding sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), and sleep efficiency over the course of 12 sessions consisting of 45 min of flotation-REST. No other treatments were offered simultaneously. Questionnaire data on insomnia severity (the ISI) and depressive severity (the MADRS) were also collected. Results: Three participants improved on their most salient insomnia symptom (long SOL or WASO), and two improved on sleep efficiency. The improvements were maintained 2 months after treatment. Insomnia severity decreased for three patients, whereas depressive severity decreased for five. No changes in TST were found and two patients did not improve on any sleep measure. The two participants who benefitted the most were students in their 20s. Discussion: The results were mixed. Flotation-REST may be beneficial for young adults with sleep-onset insomnia but more research is warranted.

ObjectivesInsufficient sleep is a public health problem that impacts the mental and physical health of children and adolescents. Complaints of insomnia are particularly pervasive among adolescents. This longitudinal study investigates factors that contribute to teen insomnia symptoms. DesignFive-year prospective follow-up study. SettingSchool-based. ParticipantsA total of 522 children (49.8% girls) aged 9.4 +/- 1.3 years at baseline; 14.4 +/- 0.7 years at follow-up. MeasurementsThe dependent variable of insomnia symptoms at follow-up was assessed with the Minimal Insomnia Symptom Scale-Revised. The independent variables at baseline were the perceived family financial situation, tiredness at school, problems waking up, short sleep duration, sleeping difficulties, having a bedroom Television (TV), and time spent with a TV/computer. Multivariate binary logistic regression analyses were used to examine whether the independent variables at baseline predicted insomnia symptoms at follow-up. ResultsPerceived quite bad/very bad family financial situation (OR 3.1; CI 1.4-6.7) and short sleep duration (<10 h) (OR 2.3; CI 1.0-5.3) among girls at baseline were associated with insomnia symptoms at follow-up. Having problems waking up among boys at baseline was associated with insomnia symptoms at follow-up (OR 4.9; CI 1.6-14.4). ConclusionShort sleep duration, problems waking up, and perceived bad family financial situation during childhood were linked with adolescent insomnia symptoms. The sex-based differences in these associations warrant further investigation to effectively mitigate adolescent insomnia.

The Minimal Insomnia Symptom Scale (MISS) is a three-item screening instrument that has been found to be psychometrically sound and capable of screening for insomnia among adults and older people. This study aimed to test the measurement properties of the MISS together with an additional item focusing on daytime functioning among adolescents using the Rasch measurement model.

Paradoxical intention (PI) has been considered an evidence-based treatment for insomnia since the 1990s, but it has not been evaluated with modern review techniques such as meta-analysis. The present study aimed to conduct the first systematic review and meta-analysis of studies that explore the effectiveness of PI for insomnia on insomnia symptomatology and theory-derived processes. A systematic review and meta-analysis was conducted by searching for eligible articles or dissertations in six online bibliographic databases. Randomised controlled trials and experimental studies comparing PI for insomnia to active and passive comparators and assessing insomnia symptoms as outcomes were included. A random effects model was estimated to determine the standardised mean difference Hedge's g at post-treatment. Test for heterogeneity was performed, fail-safe N was calculated, and study quality was assessed. The study was pre-registered at International Prospective Register of Systematic Reviews (PROSPERO, CRD42019137357). A total of 10 trials were identified. Compared to passive comparators, PI led to large improvements in key insomnia symptoms. Relative to active comparators, the improvements were smaller, but still moderate for several central outcomes. Compared to passive comparators, PI resulted in great reductions in sleep-related performance anxiety, one of several proposed mechanisms of change for PI. PI for insomnia resulted in marked clinical improvements, large relative to passive comparators and moderate compared to active comparators. However, methodologically stronger studies are needed before more firm conclusions can be drawn.