A theory-based examination of self-care behaviours among psychologists

The present study examined psychological, spiritual, physical/leisure and social self-care behaviours among psychologists using a major model of predicting human behaviour, the theory of planned behaviour (TPB). The study used a mixed method approach with two stages of data collection. Psychologists (N = 200) completed an online questionnaire assessing TPB constructs (attitude, subjective norm, perceived behavioural control and intention) and additional constructs of action planning, coping planning, peer and supervisor norms and organizational climate. Two weeks later, participants (n = 110) completed a follow-up questionnaire assessing their self-care behaviour. Results indicated general support for the standard TPB constructs in predicting self-care intentions for psychologists and the additional construct of action planning mediated the intention-behaviour relationship across most self-care dimensions. Findings from the current research provide further understanding of the factors influencing self-care engagement among psychologists and can be used to inform development of strategies to foster greater engagement in self-care behaviour.     

Preventing sleep deficit in adolescents: Long‐term effects of a quasi‐experimental school‐based intervention study

Adolescents are at risk of sleep deficit, which has serious consequences for their daytime functioning. However, school‐based interventions to improve sleep have shown limited success. This might be due to the content of the programmes (e.g., not targeting central factors such as daytime stress and technology use) or because changes have not been captured due to a lack of long‐term follow‐ups. Hence, the aim of this study was to evaluate the long‐term effects of a school‐based sleep education curriculum including time‐management training. The study used a quasi‐experimental design. Participants were 3,622 adolescents (mean age 13.7, 48% girls); 286 were in the intervention group and 3,336 were followed as a natural control group. Data were collected before the intervention and at a 1‐year follow‐up. We divided participants into three groups according to baseline sleep duration (calculated from self‐reported bed‐ and wake times, minus sleep onset latency): insufficient (<7 hr), borderline (7–8 hr) and adequate (>8 hr). Adolescents in the intervention group were ~2 times less likely to report insufficient sleep at follow‐up as compared to controls. Sleep knowledge improved significantly in the intervention group but there were no changes in emotional sleep hygiene (e.g., bedtime worry) and perceived stress. Surprisingly, technology use increased and behavioural sleep hygiene worsened in the intervention group. Although the mechanisms of change need further investigation, the results of this study point to potential long‐term benefits of school‐based sleep programmes.     

Self‐reported sleep quantity,quality and sleep hygiene in elite athletes

Sleep is essential for recovery and performance in elite athletes. While actigraphy‐based studies revealed suboptimal sleep in athletes, information on their subjective experience of sleep is scarce. Relatively unexplored is also the extent to which athletes’ sleep is adversely affected by environmental conditions and daytime behaviours, that is sleep hygiene. This study aimed to provide insight in sleep quantity, quality and its putative association with sleep hygiene. Participants were 98 elite (youth) athletes competing at the highest (inter‐)national level. Sleep quantity, quality and sleep hygiene were assessed once covering a 1‐month period by using established (sub)clinical questionnaires, and repeatedly during 7 consecutive days. Sleep quality was generally healthy, although 41% of all athletes could be classified as ‘poor sleeper’, and 12% were identified as having a sleep disorder. Daily self‐monitoring revealed sleep durations of 8:11 ± 0:45 h, but elevated wake after sleep onset of 13 ± 19 min. Sleep quality, feeling refreshed, and morning vigor were moderate at best. Regarding sleep hygiene, general measures revealed irregular sleep–wake patterns, psychological strain and activating pre‐sleep behaviours. At the daily level, blue‐light exposure and late‐evening consumption of heavy meals were frequently reported. General sleep hygiene revealed significant associations with sleep quality (0.45 < r > 0.50; P < 0.001). Results indicate that there is ample room for optimization, specifically in onset latency and in wake after sleep onset. Subtle improvements in sleep seem possible, and optimizing sleep hygiene, such as regular sleep–wake patterns and reducing psychological strain, may facilitate this sleep upgrading process.     

The link between maternal sleep and permissive parenting during late adolescence

Utilizing a multi‐method design, the present study examined the association between maternal sleep, assessed via actigraphy and self‐reports, and permissive parenting (e.g. lax, inconsistent discipline) during adolescence, as well as the extent to which this association differed by mothers’ race/ethnicity and socioeconomic status. The sample was comprised of 234 mothers (M age = 41.76 years, SD = 6.25; 67% European‐American, 31% African‐American, 2% other race/ethnicities) and 237 adolescents (113 boys, 124 girls; M age = 15.80 years, SD = 0.80; 66% European‐American, 34% African‐American). Mothers’ sleep duration (actual sleep minutes) and quality (sleep efficiency, latency, long wake episodes) were assessed using actigraphy. Mothers also reported on their sleep problems and adolescents reported on mothers’ permissive parenting behaviours. Results revealed that actigraphy‐based longer sleep duration and shorter sleep latency were associated with lower levels of permissive parenting. Further, mothers’ race/ethnicity and socioeconomic status moderated the association between actigraphy‐based sleep quality (i.e. sleep efficiency, long wake episodes) and permissive parenting. Specifically, a negative association between sleep efficiency and permissive parenting was evident only for African‐American mothers. In addition, a positive association between more frequent night wakings and permissive parenting was evident only for mothers from lower socioeconomic status households. The findings highlight the benefits of longer and higher‐quality sleep for reducing the risk of permissive parenting, especially among ethnic minority mothers and mothers from lower socioeconomic status households.     

Community violence concerns and adolescent sleep: Physiological regulation and race as moderators

Prior work has demonstrated that greater community violence concerns are associated with poor sleep quality among adolescents. However, these effects may not be uniform across all youth. The present study examined the role of individual difference variables, physiological regulation and race, as moderators of risk in the relation between adolescents’ community violence concerns and their sleep. Adolescents (N = 219; 55.3% female; 69.9% White/European American, 30.1% Black/African American) participated in the study when they were 18 years old (M = 17.7 years, SD = 1.0). Physiological regulation was assessed via respiratory sinus arrhythmia, a measure of parasympathetic regulation, at rest and in response to a stressor. Adolescents wore actigraphs for 7 nights to assess their sleep duration and quality, and reported on their community violence concerns via a well‐validated questionnaire. Results demonstrated a consistent pattern of interactions, such that African American adolescents who showed less adaptive patterns of regulating physiological arousal experienced shorter sleep duration and poorer sleep quality in the context of greater community violence concerns. Community violence concerns were not associated with sleep for White adolescents. The findings may suggest that race‐related stressors exacerbate risk for poor sleep among African American adolescents who experience more community violence concerns and have more difficulty regulating physiological arousal. Coping strategies for managing stress and arousal may be helpful for improving sleep for some youth.     

Integrating the theory of planned behaviour and self‐determination theory in health behaviour: A meta‐analysis

Purpose A meta‐analysis of studies integrating the theory of planned behaviour (TPB) and self‐determination theory (SDT) in health contexts is presented. The analysis aimed to provide cumulative empirical support for a motivational sequence in which self‐determined motivation from SDT predicts the proximal predictors of intentions and behaviour from the TPB. Methods A literature search identified 36 integrated studies providing 45 tests of effects between TPB and SDT variables. Hunter and Schmidt's (1994) methods of meta‐analysis were used to correct the effect sizes across the studies for statistical artifacts. Age (old versus young), publication status (published versus unpublished), study design (correlational versus experimental/intervention), and behaviour type (physical activity versus other health‐related behaviours) were evaluated as moderators of the effects. A path‐analysis using the meta‐analytically derived correlations was conducted to examine the proposed motivational sequence. Results Statistically significant corrected correlations were evident among the perceived autonomy support and self‐determined motivation constructs from SDT and the attitude, subjective norms, perceived behavioural control, intention, and health‐related behaviour constructs from the TPB. Only six of the 28 effect sizes were moderated by the proposed moderators. Path analysis revealed that the significant effects of self‐determined motivation on intentions and behaviour were partially mediated by the proximal predictors from the TPB. Conclusions Evidence from this synthesis supported the theoretical integration and proposed motivational sequence. Results are discussed with reference to the complementary aspects of the TPB and SDT and the need for integrated experimental or intervention studies on a broader range of health behaviours.     

Psychometric properties of the Adolescent Sleep Hygiene Scale

This study evaluated the psychometric properties of the Adolescent Sleep Hygiene Scale (ASHS), a self‐report measure assessing sleep practices theoretically important for optimal sleep. Data were collected on a community sample of 514 adolescents (16–19; 17.7 ± 0.4 years; 50% female) participating in the late adolescent examination of a longitudinal study on sleep and health. Sleep hygiene and daytime sleepiness were obtained from adolescent reports, behavior from caretaker reports, and sleep‐wake estimation on weekdays from wrist actigraphy. Confirmatory factor analysis indicated the empirical and conceptually based factor structure were similar for six of the eight proposed sleep hygiene domains. Internal consistency of the revised scale (ASHSr) was α = 0.84; subscale alphas were: physiological: α = 0.60; behavioural arousal: α = 0.62; cognitive/emotional: α = 0.81; sleep environment: α = 0.61; sleep stability: α = 0.68; daytime sleep: α = 0.78. Sleep hygiene scores were associated positively with sleep duration (r = 0.16) and sleep efficiency (r = 0.12) and negatively with daytime sleepiness (r = ?0.26). Results of extreme‐groups analyses comparing ASHSr scores in the lowest and highest quintile provided further evidence for concurrent validity. Correlations between sleep hygiene scores and caretaker reports of school competence, internalizing and externalizing behaviours provided support for convergent validity. These findings indicate that the ASHSr has satisfactory psychometric properties for a research instrument and is a useful research tool for assessing sleep hygiene in adolescents.     

Temporal associations between morningness/eveningness,problematic social media use,psychological distress and daytime sleepiness: Mediated roles of sleep quality and insomnia among young adults

The extant literature has suggested relationships between an individual's chronotype (in relation to morningness/eveningness) and several outcomes, including addictive disorders, psychological distress and daytime sleepiness. Moreover, sleep quality has been proposed to be a mediator in the aforementioned relationships. Consequently, the aim of the present study was to investigate the complex relationship between morningness/eveningness, problematic social media use, psychological distress and daytime sleepiness, with the potential mediators of sleep quality and insomnia. All participants (N = 1,791 [30.1% males]; mean age = 27.2 years, SD = 10.1) completed a battery of psychometric scales, including a reduced version of the Morningness‐Eveningness Questionnaire (at baseline), the Pittsburgh Sleep Quality Index and Insomnia Severity Index (1 month after baseline assessment), the Bergen Social Media Addiction Scale, the Hospital Anxiety and Depression Scale, and the Epworth Sleepiness Scale (2 months after baseline assessment). The impacts of morningness‐eveningness on problematic social media use, anxiety, depression and daytime sleepiness were found in the mediation models. Furthermore, the mediated effects of insomnia and sleep quality were observed. The present study's results emphasize the importance of promoting healthy sleep habits and sleep hygiene behaviours, and that of early detection of sleep problems among individuals who have the eveningness chronotype, because this would significantly improve their health outcomes.     

The impact of prolonged violent video‐gaming on adolescent sleep: an experimental study

Video‐gaming is an increasingly prevalent activity among children and adolescents that is known to influence several areas of emotional, cognitive and behavioural functioning. Currently there is insufficient experimental evidence about how extended video‐game play may affect adolescents' sleep. The aim of this study was to investigate the short‐term impact of adolescents' prolonged exposure to violent video‐gaming on sleep. Seventeen male adolescents (mean age = 16 ± 1 years) with no current sleep difficulties played a novel, fast‐paced, violent video‐game (50 or 150 min) before their usual bedtime on two different testing nights in a sleep laboratory. Objective (polysomnography‐measured sleep and heart rate) and subjective (single‐night sleep diary) measures were obtained to assess the arousing effects of prolonged gaming. Compared with regular gaming, prolonged gaming produced decreases in objective sleep efficiency (by 7 ± 2%, falling below 85%) and total sleep time (by 27 ± 12 min) that was contributed by a near‐moderate reduction in rapid eye movement sleep (Cohen's d = 0.48). Subjective sleep‐onset latency significantly increased by 17 ± 8 min, and there was a moderate reduction in self‐reported sleep quality after prolonged gaming (Cohen's d = 0.53). Heart rate did not differ significantly between video‐gaming conditions during pre‐sleep game‐play or the sleep‐onset phase. Results provide evidence that prolonged video‐gaming may cause clinically significant disruption to adolescent sleep, even when sleep after video‐gaming is initiated at normal bedtime. However, physiological arousal may not necessarily be the mechanism by which technology use affects sleep.     

Chronic sleep reduction is associated with academic achievement and study concentration in higher education students

Inadequate sleep impairs cognitive function and has been associated with worse academic achievement in higher education students; however, studies that control for relevant background factors and include knowledge on sleep hygiene are scarce. This study examined the association of chronic sleep reduction (i.e. symptoms of chronic sleep reduction such as shortness of sleep, sleepiness and irritation), subjective sleep quality and sleep hygiene knowledge with academic achievement (grades and study credits) and study concentration among 1378 higher education students (71% female, mean age 21.73 years, SD = 3.22) in the Netherlands. Demographic, health, lifestyle and study behaviour characteristics were included as covariates in hierarchical regression analyses. After controlling for significant covariates, only chronic sleep reduction remained a significant predictor of lower grades (last exam, average in current academic year). Better sleep quality and sleep hygiene knowledge were associated with better academic achievement, but significance was lost after controlling for covariates, except for a remaining positive association between sleep hygiene beliefs and grades in the current academic year. Moreover, better sleep quality and lower scores on chronic sleep reduction were associated with better study concentration after controlling for significant covariates. To conclude, chronic sleep reduction is associated with academic achievement and study concentration in higher education students. Inadequate sleep hygiene knowledge is moderately associated with worse academic achievement. Future research should investigate whether sleep hygiene interventions improve academic achievement in students of higher education.     

Behavioural and emotional profiles of children and adolescents with disorders of arousal

Disorders of arousals are common sleep disorders characterized by complex motor behaviours that arise episodically out of slow‐wave sleep. Psychological distress has long been associated with disorders of arousal, but this link remains controversial, especially in children and adolescents. The aim of this multi‐centre study was to characterize behavioural and emotional problems in a sample of children/adolescents with disorders of arousal, and to explore their relationship with the severity of nocturnal episodes. The parents of 41 children/adolescents with a diagnosis of disorders of arousal (11.5 ± 3.3 years old, 61% males) and of a group of 41 age‐ and gender‐matched control participants filled in the Child Behavior Checklist, along with the Sleep Disturbance Scale for Children and the Paris Arousal Disorders Severity Scale. Multilevel t‐tests revealed significantly higher total scores and sub‐scores of the Child Behavior Checklist for the patient group compared with the control group. Thirty‐four percent of the patients obtained pathological total scores, and 12% of them borderline scores. The severity of emotional/behavioural problems in the patient group was positively correlated with the severity of the nocturnal episodes. Interestingly, children/adolescents with disorders of arousal also obtained higher excessive daytime sleepiness and insomnia symptoms sub‐scores at the Sleep Disturbance Scale for Children. These results confirmed the hypothesis that behavioural/emotional problems are surprisingly common in children/adolescents with disorders of arousal. Further studies are warranted to investigate the causal relationship between pathological manifestations, subtler sleep abnormalities, and diurnal emotional/behavioural problems in children/adolescents with disorders of arousal.     

Role of anticipated regret,intentions and intention stability in adolescent smoking initiation

Objectives To examine the impact of anticipated regret within the theory of planned behaviour (TPB) on intentions of adolescents to initiate smoking. To examine the moderating role of anticipated regret and intention stability on the relationship between intentions and smoking initiation in adolescents. Methods We conducted two studies measuring anticipated regret within the TPB applied to adolescent smoking initiation. In the first study, 347 non‐smoking adolescents (between 11 and 12 years of age) completed the TPB and anticipated regret measures about smoking initiation. In the second study, 675 non‐smoking adolescents (between 11 and 12 years of age) completed the TPB, anticipated regret, and intention stability measures in relation to smoking initiation. Smoking was assessed objectively by carbon monoxide breath monitor 9 months later. Results In Studies 1 and 2, regret significantly added to predictions of intentions over and above components of the TPB (p <.001). In Study 2, smoking behaviour was predicted by intentions and the relationship of intentions to behaviour was moderated by regret and intention stability. Conclusions Regret and intention stability were shown to be important variables within the TPB in understanding intentions and behaviour of smoking initiation in adolescents.     

Profiles of sleep changes during the COVID‐19 pandemic: Demographic,behavioural and psychological factors

This study aimed to evaluate changes in sleep during the COVID‐19 outbreak, and used data‐driven approaches to identify distinct profiles of changes in sleep‐related behaviours. Demographic, behavioural and psychological factors associated with sleep changes were also investigated. An online population survey assessing sleep and mental health was distributed between 3 April and 24 June 2020. Retrospective questions were used to estimate temporal changes from before to during the outbreak. In 5,525 Canadian respondents (67.1% females, 16–95 years old: Mean ± SD = 55.6 ± 16.3 years), wake‐up times were significantly delayed relative to pre‐outbreak estimates (p < .001,  = 0.04). Occurrences of clinically meaningful sleep difficulties significantly increased from 36.0% before the outbreak to 50.5% during the outbreak (all p < .001, g ≥ 0.27). Three subgroups with distinct profiles of changes in sleep behaviours were identified: “Reduced Time in Bed”, “Delayed Sleep” and “Extended Time in Bed”. The “Reduced Time in Bed” and “Delayed Sleep” subgroups had more adverse sleep outcomes and psychological changes during the outbreak. The emergence of new sleep difficulties was independently associated with female sex, chronic illnesses, being employed, family responsibilities, earlier wake‐up times, higher stress levels, as well as heavier alcohol use and television exposure. The heterogeneity of sleep changes in response to the pandemic highlights the need for tailored interventions to address sleep problems.     

Evaluating the impact of method bias in health behaviour research: a meta-analytic examination of studies utilising the theories of reasoned action and planned behaviour

The methods employed to measure behaviour in research testing the theories of reasoned action/planned behaviour (TRA/TPB) within the context of health behaviours have the potential to significantly bias findings. One bias yet to be examined in that literature is that due to common method variance (CMV). CMV introduces a variance in scores attributable to the method used to measure a construct, rather than the construct it represents. The primary aim of this study was to evaluate the impact of method bias on the associations of health behaviours with TRA/TPB variables. Data were sourced from four meta-analyses (177 studies). The method used to measure behaviour for each effect size was coded for susceptibility to bias. The moderating impact of method type was assessed using meta-regression. Method type significantly moderated the associations of intentions, attitudes and social norms with behaviour, but not that between perceived behavioural control and behaviour. The magnitude of the moderating effect of method type appeared consistent between cross-sectional and prospective studies, but varied across behaviours. The current findings strongly suggest that method bias significantly inflates associations in TRA/TPB research, and poses a potentially serious validity threat to the cumulative findings reported in that field.     

Teenage night owls or early birds? Chronotype and the mental health of adolescents

Evidence suggests that the timing of sleep (chronotype) impacts mental health in young people, but previous studies have not accounted for sleep duration or school start time in this association, or examined a broad range of mental outcomes. In this study, we investigated the association between chronotype and mental health in a representative sample of adolescents from the 2014 Canadian Health Behaviour in School‐Aged Children survey (29,635 students, 362 schools). We examined positive and negative aspects of mental health, using scores for emotional problems (range 0–33), emotional well‐being (0–22), behavioural problems (0–28) and prosocial behaviours (0–25). We estimated chronotype using the time of mid‐sleep on weekends and examined the associations using multilevel regressions, adjusted for sleep duration, school start time, individual, family and geographic characteristics. The average time of mid‐sleep (chronotype) was 04:11 hr. An hour delay in mid‐sleep time was associated with more emotional problems (0.34 [95% confidence interval 0.23, 0.45] point higher score), more behavioural problems (2.0% [95% confidence interval 1.4%, 2.6%] higher score), less emotional well‐being (0.19 [95% confidence interval 0.09, 0.20] point lower score), and fewer prosocial behaviours (0.18 [95% confidence interval 0.08, 0.29] point lower score). A later chronotype was associated with poorer mental health, independent of sleep duration and school start time, and across internalizing and externalizing mental health domains. Further research is needed to clarify the mechanisms underlying this association. The timing of sleep, and not just its duration, may be an additional consideration for youth mental health.     

Self‐administered acupressure for insomnia disorder: a pilot randomized controlled trial

Self‐administered acupressure has potential as a low‐cost alternative treatment for insomnia. To evaluate the short‐term effects of self‐administered acupressure for alleviating insomnia, a pilot randomized controlled trial was conducted. Thirty‐one subjects (mean age: 53.2 years; 77.4% female) with insomnia disorder were recruited from a community. The participants were randomized to receive two lessons on either self‐administered acupressure or sleep hygiene education. The subjects in the self‐administered acupressure group (n = 15) were taught to practise self‐administered acupressure daily for 4 weeks. The subjects in the comparison group (n = 16) were advised to follow sleep hygiene education. The primary outcome was the Insomnia Severity Index (ISI). Other measures included a sleep diary, Hospital Anxiety and Depression Scale and Short‐form Six‐Dimension. The subjects in the self‐administered acupressure group had a significantly lower ISI score than the subjects in the sleep hygiene education group at week 8 (effect size = 0.56, P = 0.03). However, this observed group difference did not reach a statistically significant level after Bonferroni correction. With regard to the secondary outcomes, moderate between‐group effect sizes were observed in sleep onset latency and wake after sleep onset based on the sleep diary, although the differences were not significant. The adherence to self‐administered acupressure practice was satisfactory, with 92.3% of the subjects who completed the lessons still practising acupressure at week 8. In conclusion, self‐administered acupressure taught in a short training course may be a feasible approach to improve insomnia. Further fully powered confirmatory trials are warranted.     

Investigating mothers' decisions about their child's sun-protective behaviour using the Theory of Planned Behaviour

This study tested the utility of the Theory of Planned Behaviour (TPB) to predict mothers' decisions to ensure their child engages in sun-protective behaviours. Mothers (N = 162) of children aged four or five years completed standard TPB items (attitude, subjective norm, perceived behavioural control, intention) and additional variables of role construction, mothers' own sun safe behaviour, planning and past behaviour. One week later, participants (N = 116) reported their behaviour. Results found support for the TPB constructs, role construction, past behaviour and the mediating role of planning. These findings can inform strategies to prevent skin cancer.     

Testing an extended theory of planned behaviour to predict young people's sun safety in a high risk area

Objectives The present research examined the sun protection intentions and behaviours of young people in a high risk skin cancer area using an extended theory of planned behaviour (TPB) incorporating additional social influences of group and image norms. Design The study employed a prospective design to examine young people's sun protection intentions and behaviour. Method Participants (N = 1,134), aged 12–20 years, were students (school, university, TAFE) and young employees living in Queensland, Australia. Participants completed a questionnaire assessing the TPB predictors (attitude, subjective norm, perceived behavioural control) and additional social influences (group norm, image norm) of sun protection intentions. Two weeks later, participants (N = 734) reported their sun protection behaviour for the previous fortnight. Results Results revealed that the TPB variables of attitude, subjective norm and perceived behavioural control and the additional social influence variable of group norms, but not image norms, emerged as significant predictors of intentions to engage in sun protection. The extended TPB variables accounted for 36% of the variance in intentions. For behaviour, the extended TPB variables accounted for 27% of the variance with both intention and, unexpectedly, group norm as the significant direct predictors of sun protective behaviours. Conclusions Results of this study provide support for the application of the TPB in the sun safety context and highlight the importance of considering the influence of group norms in the development of future interventions to increase young people's sun protection intentions and behaviour.     

Subjective–objective sleep discrepancy in patients with insomnia during and after cognitive behavioural therapy: An actigraphy study

Although patients with insomnia often show a discrepancy between self‐reported and objective sleep parameters, the role of and change in this phenomenon during treatment remain unclear. The present study aimed to assess the effect of cognitive behavioural therapy for insomnia on subjective and objective sleep discrepancy of total sleep time, sleep‐onset latency and wake after sleep onset. The total sleep time discrepancy was also assessed across the entire therapy. The second aim was to examine the treatment outcome of two insomnia groups differing in sleep perception. Thirty‐six adults with insomnia (mean age = 46.7 years, SD = 13.9; 22 females) were enrolled in the final analyses. Patients underwent a 6‐week group cognitive behavioural therapy for insomnia programme. Sleep diary and actigraphy measurements were obtained during the therapy. Patients who underestimated total sleep time (n = 16; underestimating group) were compared with patients who accurately perceived or overestimated total sleep time (n = 20; accurate/overestimating group). After cognitive behavioural therapy for insomnia, a significant decrease of total sleep time and sleep‐onset latency discrepancy was observed without a change in wake after sleep onset discrepancy in the total sample. Only the underestimating group reported decreased sleep‐onset latency discrepancy after the treatment, whereas total sleep time discrepancy significantly changed in both groups. The underestimating group showed a significant decrease of total sleep time discrepancy from Week 1 to Week 2 when the sleep restriction was implemented, whereas the accurate/overestimating group showed the first significant change at Week 4. In conclusion, both groups differing in sleep perception responded similarly to cognitive behavioural therapy for insomnia, although different In conclusion, both groups differing in sleep perception responded similarly to cognitive behavioural therapy for insomnia, although different therapeutic components could play important roles in each group. components could play important roles in each group.