key: cord-0857709-x36m6ahv
authors: Simor, Péter; Polner, B; Báthori, N; Sifuentes-Ortega, R; Van Roy, A; Albajara Sáenz, A; Luque González, A; Benkirane, O; Nagy, T; Peigneux, P
title: Home confinement during the COVID-19: day-to-day associations of sleep quality with rumination, psychotic-like experiences, and somatic symptoms
date: 2021-02-10
journal: Sleep
DOI: 10.1093/sleep/zsab029
sha: 6e900c540dba1dfda472fc589b5f496ba1a7d82e
doc_id: 857709
cord_uid: x36m6ahv

Due to the COVID-19 pandemic, populations from many countries have been confined at home for extended periods of time in stressful environmental and media conditions. Cross-sectional studies already evidence deleterious psychological consequences, with poor sleep as a risk factor for impaired mental health. However, limitations of cross-sectional assessments are response bias tendencies, and the inability to track daily fluctuations in specific subjective experiences in extended confinement conditions. In a prospective study conducted across three European countries, we queried participants (N = 166) twice a day through an online interface about their sleep quality and their negative psychological experiences for two consecutive weeks. Focus was set on between-and within-person associations of subjective sleep quality with daytime experiences such as rumination, psychotic-like experiences, and somatic complaints about the typical symptoms of the coronavirus. Results show that daily reports of country-specific COVID-19 deaths predicted increased negative mood, psychotic-like experiences and somatic complaints during the same day, and decreased subjective sleep quality the following night. Disrupted sleep was globally associated with negative psychological outcomes during the study period, and a relatively poorer night of sleep predicted increased rumination, psychotic-like experiences, and somatic complaints the following day. This temporal association was not paralleled by daytime mental complaints predicting relatively poorer sleep quality on the following night. Our findings show that night-to-night changes in sleep quality predict how individuals cope the next day with daily challenges induced by home confinement.

In December 2019 a new coronavirus (SARS-CoV-2) was identified as the pathogen of an acute respiratory syndrome reported first in Wuhan, China 1 

Organization announced the disease (eventually named COVID-19) as a public health emergency of international concern 2 , and in the next three months, the COVID-19 continued to spread all over the world rapidly growing into a global pandemic. In order to slow the propagation of the virus as well as to attenuate the burden on health care systems, many countries introduced unprecedented measures of home confinement requiring individuals to stay at home and limit outdoor activities to the most necessary purposes. The restrictions drastically changed many individuals' daily routines that within the menacing context of the pandemic could lead to severe mental health complaints 3, 4 , requiring health professionals to consider the psychological impact of COVID-19 5, 6 . A number of cross-sectional surveys conducted amongst front-line medical staff 7,8 , university students 9,10 , and the general population [11] [12] [13] corroborated the concerns regarding mental health by reporting a pronounced increase in anxiety, depression, and symptoms of posttraumatic stress disorder (PTSD). Beyond these warning signs of psychological distress, a great proportion of the respondents reported frequent sleep difficulties 11, 13, 14 and poor sleep emerged as an important risk factor for mental health complaints 3 . Additionally, disrupted sleep mediated the link between threat perception (measured by the COVID-19 death count) and negative emotions in a longitudinal study 15 , and those who reported more sleep difficulties during than before the confinement exhibited higher levels of depression, anxiety, and stress 16 A c c e p t e d M a n u s c r i p t Limitations of the above studies are that sleep quality and daytime symptoms were measured retrospectively (e.g. asking participants to rate sleep quality during the previous weeks or month) and data were collected using cross-sectional designs.

Although the approach allows quick and economical assessments in large samples, it is extremely difficult in such designs to address the directionality of the associations (i.e., whether sleep disruption temporally predicts daytime dysfunctions or the other way around). In addition, retrospective questionnaires might be more prone to biases 26, 27 , especially when individuals are queried in extremely unusual and stressful circumstances such as the COVID-19 pandemic. Studies indicate that retrospective selfreports are strongly biased by negative mood states 27 , are subject to contamination between scales due to response bias tendencies 28 , and show little agreement with prospectively assessed measures of similar variables 29 . Furthermore, retrospective cross-sectional studies can only account for differences between individuals and neglect intra-individual variability (i.e. moment-to-moment changes in sleep and mental complaints within the same individuals), whereas prospective assessments point to considerable within-subject variability in sleep quality 30, 31 , daytime affective states 32, 33 , and even in states associated with personality traits that are considered to be stable over time 34 .

To overcome these limitations, we conducted a two-week, prospective study investigating the associations between subjective sleep quality and daytime experiences during the confinement of the COVID-19 pandemic. Our prospective data collection allowed us to simultaneously examine associations across and within individuals.

Hence, we tested whether individuals with poor sleep exhibited a higher level of mental health complaints during the two-week assessment period, and whether subtle nightto-night fluctuations in sleep quality were prognostic of increased negative experiences the next day (within individuals). To address the temporal directionality of these associations, we examined whether subtle changes in daytime reports predicted changes in subjective sleep quality the following night.

Widely used measures of anxiety, depression, and stress provide efficient means to estimate the severity of negative affect and the prevalence of psychopathological conditions 3,12 , but are not capable of capturing more specific and transient mental A c c e p t e d M a n u s c r i p t experiences that may impose an emotional burden on individuals during home confinement. Here, we focused on three factors particularly relevant within the context of the COVID-19 pandemic: rumination, psychotic-like experiences, and somatic complaints mimicking symptoms of COVID-19. Rumination refers to repetitive, intrusive, and hardly controllable thoughts about self-relevant situations and their underlying causes, and appears as a transdiagnostic factor in various psychopathological states 35,36 . Rumination exhibits transient, state-like variations in healthy individuals and is associated with neurophysiological indices of impaired emotional adaptation 37 . We assumed that the unpredictable nature of the pandemic might facilitate ruminative thoughts about the virus and the confinement, and given the previously reported links between rumination and sleep quality 38 , we expected that increased rumination would be linked to impaired sleep. Importantly, rumination predicts key mental health outcomes such as depression 39 and paranoia 40 .

Psychotic-like experiences are unusual subjective experiences that phenomenologically resemble the symptoms of psychosis at a subclinical level (e.g., difficulties in controlling thoughts, cognitive anomalies, strange perceptions, and paranoid ideas), which are relatively common in the general population 41 . Psychotic-like experiences also exhibit considerable moment-to-moment fluctuations 42, 43 and may increase under stressful circumstances 42, 44 , and after disrupted sleep 30, 43, 45 . We reasoned that psychotic-like experiences represented another particularly relevant psychological reaction to the stressful aspects of the confinement periods such as social isolation 46 , and increased uncertainty of the environment. From a public mental health perspective, it is crucial that distressing subthreshold psychotic-like experiences predict the risk of developing clinically relevant psychosis 47 . Coronavirus anxiety (the fear of obtaining the virus) emerged as a novel mental health issue of severe concern 48 that was associated with a number of psychological difficulties. Therefore, somatic complaints mimicking the most common symptoms of COVID-19 were examined as a measure of somatic symptom severity 49 possibly related to the health anxiety provoked by the pandemic. Although day-to-day (intra-individual) fluctuations of somatic symptoms were mainly evidenced in clinical populations 50, 51 , healthy individuals might also express pronounced variability in somatic symptoms in the context of the unprecedented coronavirus pandemic. We thus hypothesized that sleep disruptions would be associated with A c c e p t e d M a n u s c r i p t rumination, psychotic-like experiences, and somatic complaints during the study period, and that nights of poor sleep quality would eventually lead to more symptoms the following day within an individual. Likewise, we examined the inverse direction, i.e., whether daytime rumination, psychotic-like experiences, and somatization could predict worse sleep quality the following night. Additionally, we reasoned that trait-like characteristics such as proneness for a dysregulated stress-response after exposure to a stressor (as reflected by PTSD-like symptoms 52, 53 ) and difficulties in controlling thoughts and attention (as reflected by cognitive disorganization 54, 55 ) would be predictive of increased maladaptation during the pandemic. Therefore, we examined the association of these retrospectively assessed psychopathological indices with daytime complaints over and above the hypothesized association with sleep.

Participants. Individuals (N = 728, 556 (76%) females, age = 18-69 years, Mean age = 28.5, SD age = 10.09) willing to participate in our study were selected from three European countries in which restrictive confinement measures were adopted. The majority of the respondents were young, university students and their family members.

Participants were contacted by advertisements placed on social media, and through the web pages and mailing services of the participating universities (Université Libre de Bruxelles, Belgium, Eötvös Loránd University, Hungary, and Autonomous University of Madrid, Spain). In the first phase of the study, participants were asked to complete an online questionnaire including self-report scales of standardized questionnaires measuring sleep quality 56 , depression 57 , schizotypy 58 , and symptoms of PTSD 59 .

Demographic variables and items related to events (e.g. tested positive for COVID -19) and experiences related to the confinement (e.g. household, school-and work-related stress) were also assessed. This cross-sectional questionnaire served us to screen and select the participants for the second, prospective phase of the study. Individuals with current or prior history of neurological, psychiatric, or chronic somatic diseases, scoring above 12 on the short form of the Beck Depression Inventory (BDI-13 57 ), or taking medication (except contraceptives) were excluded. In addition, we excluded participants who reported to be previously diagnosed with COVID-19 or believed that they currently suffered or had suffered but recovered from the virus. Individuals fulfilling the inclusion criteria and willing to continue participation (N = 246) were A c c e p t e d M a n u s c r i p t selected for the prospective study phase. 184 individuals (146 (79 %) females, age 18-69 years, Mage = 26.28, SD = 7.42) were assigned for the second phase of the study assessing daily questionnaires during two weeks. Informed consents were obtained, and the study was approved by the corresponding local ethical committees of the three participating universities, the local Ethics Committee of the Université Libre de Bruxelles, the Ethics Committee of the Eötvös Loránd University, and the Ethics Committee of the Autonomous University of Madrid, respectively.

Procedure. The study consisted of three phases: 1) the administration of the crosssectional questionnaire to screen and enroll potential participants, 2) the prospective study phase asking participants to complete short questionnaires twice a day during two consecutive weeks, and 3) the debriefing phase. The same questionnaire-batteries were used for the Belgian, Hungarian, and Spanish samples using the standardized or available versions in English, Hungarian, and Spanish, respectively. Single items were created in each language by the respective native speaker authors of the research team.

Items that were not available in one language were translated by the native speaker members of the research team. Research assistants invited the selected participants to sign up for the prospective phase of the study through a dedicated website where only the invited participants could register and approve their registration via a two-step authentication process. Participants signed up between the 9 th of April 2020 and the 14 th of May 2020 for the two-week assessment period (See Figure 1 showing the twoweek assessment period within the timeline of the pandemic). Daily questionnaires requiring approximately 3-5 minutes per day were sent to participants via the online interface. A morning questionnaire was available between 5:00 and 12:30, and an evening questionnaire was accessible between 18:00 and 03:00. Participants were instructed to complete the morning questionnaire upon awakening, and to complete the second questionnaire always before going to sleep. A reminder email of the morning questionnaire was sent between 7:00-9:00, and a reminder of the second questionnaire was sent between 19:00-20:00. The two-week long prospective study period started with the first morning questionnaire the day after the participant completed the registration and ended on the 14 th day with the last evening questionnaire. Morning questionnaires assessed subjective sleep quality and sleep schedules (bedtime, sleep latency, and wake up time). The evening questionnaires consisted of items measuring A c c e p t e d M a n u s c r i p t mood, rumination, psychotic-like experiences and somatic complaints comprising the most typical symptoms of the COVID-19. Participants were also asked to report daily caffeine intake and alcohol consumption and their overall satisfaction with daily activities (work, physical activity, social interactions, media use, etc.). After finishing the last questionnaire, participants were instructed to access the debriefing that consisted of a final phase providing the possibility for the participants to ask questions regarding the study and to report any issue that they considered important. Moreover, they were asked to report if they had been tested positive for COVID-19 and if they assumed that they had contracted the virus during the study period.

Cross-sectional measures. The PTSD Checklist from the DSM-5 (PCL-5) was used to assess PTSD-like symptoms 59 . This 20-item self-report questionnaire that assesses DSM-5 symptoms of PTSD is suitable to screen individuals for PTSD, but it can also be applied Psychotic-like experiences were assessed with a scale consisting of eight items that were originally adapted from two validated instruments 42, 63 . The items (rated on an 8point Likert scale) covered perceptual anomalies (e.g. "Familiar things have seemed strange or unusual"), cognitive disorganization (e.g. "I have found it difficult to think clearly") and paranoid ideation (e.g. "I think people have been saying or doing things to annoy me."). The scale showed good psychometric properties and proved to be effective for the daily assessment of psychotic-like experiences in a previous study 43 . Somatic complaints were measured by items adopted from the Patient Health Questionnaire (PHQ-15) 49 . The PHQ-15 was designed to measure the prevalence of the most common body symptoms (e.g., headache, nausea, etc.). Here, we used items that overlapped with the most typical symptoms of the coronavirus such as stomach pain, headache, chest pain, dizziness, low energy, muscle pain, shortness of breath, and we added an extra item concerning the experience of dry cough or sore throat. Daytime mood was assessed by a single item ("Throughout the day my mood was...") rated on an 8-point M a n u s c r i p t Likert scale (0 -Extremely negative: sad, negative, distressed; 7 -Extremely positive: happy, joyful, relaxed).

Statistical analyses. In order to account for the nested structure of the data (repeated measures within participants), linear mixed models were fitted using the lme4 package 64 in R (v3.6.3). Every model included a random intercept and random slope per participant for the within-person centered time-varying predictor. In case of convergence issues, random slopes were removed, and a random intercept-only model was fitted. We disentangled between-and within-person effects of time-varying variables obtained from the prospective study 65 . Within-person averages over the twoweek study period were entered to assess between-person effects (i.e. to capture differences between participants scoring high or low on a measure on average), while within-person centering was applied to examine within-person effects (i.e. to capture correlates of day-to-day deviation from the participant's average on a measure). When we fitted models that included somatic complaints, we excluded data from eight participants who indicated at debriefing phase that they believed they had contracted the coronavirus during their participation in the study. Autocorrelation was taken into account in all the examined models detailed below. Therefore, each dependent variable was also predicted by the same variable at the preceding time point (i.e. preceding day).

The reason to include an autocorrelation parameter in the models was to control for carryover effects in our measures of interest.

First, we investigated how events associated with the pandemic predicted daytime mental health complaints, sleep disruption, and sleep duration. Predictors were country-wise and worldwide numbers of COVID-related deaths for the given day Then, we analyzed the relationship between sleep disruption / duration and mental health complaints on the next day. Dependent variables were the sum scores derived from the prospective measurements of rumination, psychotic-like experiences, and somatic complaints. As diagnostic plots suggested that model residuals were not normally distributed, each dependent variable was log10-transformed, after which model residuals did not appear to strongly violate normality. Age, gender, PTSD-like symptoms (PCL-5 sum score), cognitive disorganization and within-person mean of subjective sleep disruption (GSQS sum score) / duration were entered as level-2 predictors, and within-person centered subjective sleep quality / duration were entered as a level-1 predictor in the models.

In the analysis of the relationship between daytime mental health complaints and sleep disruption / duration the following night, the dependent variables were sleep quality (GSQS sum score) and sleep duration. Age, gender, PTSD-like symptoms (PCL-5 sum score), cognitive disorganization and within-person means of mood, rumination, psychotic-like experiences and somatic complaints were entered as level-2 predictors, and within-person centered mood, rumination, psychotic-like experiences and somatic complaints (of the day before sleep) were entered as level-1 predictors. The p-values corresponding to the analyses of sleep-related variables (both level-1 and level-2 predictors) were adjusted by the Benjamini-Hochberg procedure of False Discover Rate (FDR) to address the issue of multiple comparisons 66 .

In the first phase of the study, participants from three European countries in which restrictive confinement measures were adopted (Belgium, Hungary, and Spain) responded to a survey including items addressing cognitive disorganization, posttraumatic stress symptoms, sleep Table 2 for statistical parameters). Table 3 . Subjective sleep quality was associated with rumination in both cases: more disrupted sleep (on average) was associated with increased rumination over the two-week study period, and a relatively poorer night of sleep (i.e. reduction of sleep quality compared to the individual, two-week average) predicted relatively increased rumination the following day. In addition, trait-like, retrospective measures of posttraumatic symptoms (assessed by the PCL-5), and cognitive disorganization were both predictive of increased rumination over the study period (See Table 3 ).

Next, we performed a similar analysis regressing the same variables on psychotic-like experiences. As expected, worse sleep quality was globally associated with increased A c c e p t e d M a n u s c r i p t reports of psychotic-like experiences. Moreover, night-to-night changes in sleep quality within individuals were also linked to increased psychotic-like experiences the following day, that is, worse sleep quality predicted more psychotic-like experiences the next day. PTSD-like symptoms and cognitive disorganization (were both predictive of increased psychotic-like experiences (see Figure 4 /B and Table 3 ).

Likewise, we investigated the links between sleep disruption and the daily experience of somatic symptoms of the COVID-19. At the between-subject level, subjective sleep disruption was positively associated with reports of somatic symptoms: the withinperson average of sleep disruption was associated with a higher rate of somatic complaints over the course of the study. Regarding daily fluctuations within individuals, relatively worse sleep quality on a given night was associated with more severe somatic symptoms the following day. PCL-5 scores and cognitive disorganization both emerged as significant predictors of (increased) somatic symptoms in the statistical model (see Table 3 ).

In sum, disrupted sleep was associated with increased rumination, psychotic-like experiences, and somatic symptom severity as measured prospectively during the twoweek study period. Moreover, night-to-night variations in subjective sleep quality predicted next-day's functioning, indicating that a relatively worse night of sleep was more likely to lead to increased rumination, psychotic-like experiences, and somatic symptoms the following day.

Subjective sleep duration is not predictive of daytime mental complaints. In contrast to subjective sleep quality, sleep duration on average or daily fluctuations of the duration of sleep were not associated with daytime rumination, psychotic-like experiences, or somatic complaints (Table 3) . Table S1 -Supplementary Materials). These findings suggest that negative mood did not fully account for the associations of sleep disruption with rumination, psychotic-like experiences, and somatic symptoms.

Daytime mental complaints and sleep quality and duration the following night. To investigate bidirectional relationships regarding day-to-day associations between sleep and daytime mental health problems, we also examined the temporal associations between daytime mental health complaints and sleep on the following night. Daily rates of rumination, psychotic-like experiences, or negative mood did not significantly predict subjective sleep disruption and sleep duration the following night. Interestingly, daytime somatic complaints showed a negative association with sleep disruption the following night, that is, more somatic complaints during the day (relative to one's own average) were followed by better sleep quality the following night. On the other hand, higher average level of somatic complaints reported during the study period was associated with poorer sleep quality as shown by a positive association between somatic complaints. Nevertheless, the associations between somatic-complaints and sleep disruption did not remain significant after the statistical correction for multiple comparisons. In addition, older age was associated with poorer sleep quality (on average) during the two-week assessment period (See Table 4 ). In sum, whereas sleep disruption predicted more mental complaints the following day, such temporal associations in the other direction were only observed at a trend-level in case of withinperson changes in somatic complaints, whose increases were somewhat paradoxically associated with improvement of subjective sleep quality.

Carryover effects from day-to-day within variables. In order to account for carryover effects and to verify whether the associations between sleep and next day's mental health complaints remain significant regardless of the day-to-day associations between the variables, we included the autoregressive parameter in each model. More specifically, outcome variables were also predicted by their respective values at previous time points (autoregressive parameter). This way, we aimed to rule out that the associations between night-time sleep and next day's complaints were not due to carryover effects of mental health complaints from day-to-day (i.e. mental health A c c e p t e d M a n u s c r i p t

. We observed significant positive autocorrelation for psychotic-like experiences, rumination, and somatic complaints, suggesting that within-person increases / decreases in these aspects of mental health problems tend to carry over days. Furthermore, we detected that sleep duration had a significant negative autocorrelation, implicating that participants in the sample tended to catch up with sleep debt and to sleep less when they slept more the night before (Table 4) . Importantly, sleep quality predicted next day's mental complaints (Table 3 and Figure 4 ) regardless of these carryover effects.

The aim of our study was to prospectively investigate the associations between Noticeably, temporal associations between sleep and daytime mental health complaints were not consistent in the reverse direction. Simply put, worse days were not followed by worse nights. Such associations (i.e., daytime stress leading to sleep disruption the following night) have been reported in some studies 38,87,88 , but others found only unidirectional links between sleep quality and next day's psychopathological outcomes 32, 89, 90 . Although a bidirectional relationship between sleep and daytime mental health seems plausible 77 , future studies and meta-analyses should corroborate if associations are present in both directions. Interestingly, days with more somatic complaints were followed by less disrupted sleep the following night, although the association was not significant after the correction for multiple comparisons. Although the interpretation of this finding remains elusive, we may speculate that somatic complaints increase fatigue and the homeostatic pressure for sleep. Since we restricted our analyses to individuals who did not self-report prior or current pathological conditions, or above-threshold levels of self-reported depressive states, we cannot here generalize our findings to high- A c c e p t e d M a n u s c r i p t

The study was supported by the (Hungarian) National Research, Development and

Innovation Office (NKFI/OTKA K 128599 and NKFI FK 128100; ELTE Thematic Excellence

Programme 2020 TKP2020-IKA-05) and by the BME-Biotechnology FIKP grant of EMMI (BME FIKP-BIO).

Non-financial disclosure: The authors have no conflicts of interest to declare.

The methods were carried out in accordance with the relevant guidelines and regulations.

Anonymized data and analysis scripts can be found on the project's OSF page https://osf.io/xabwe/?view_only=f319528ac4c54e08bb041c788dcb6339 M a n u s c r i p t M a n u s c r i p t Daily reports of COVID-19 deaths were predictive of increased negative mood, more psychotic-like experiences, and somatic complaints during the day, and worse subjective sleep quality the following night. Daily reports of rumination, psychotic-like experiences, and somatic symptoms decreased as time elapsed since the introduction of the confinement, but we also observed a quadratic effect indicating that the amelioration of mental health exhibited a slowing trend. In the plots, each point represents the average of the given measure for a day within a country and the trend lines are weighted for the number of observations for the given day in a country. Shades show 95% confidence intervals. Note that confidence intervals become wider due to a lower number of observations around later time points after the introduction of the confinement. Left column: Individual differences in subjective sleep disruption are associated with increased rumination, psychotic-like experiences, and somatic complaints during the two-week study period. The scatterplots of the left column represent the two-week averages of sleep disruption (x-axes) and daytime experiences (y-axes). Points with brighter and darker colors indicate positive and negative ratings of mood, respectively. Note that the brighter colored points (reflecting more positive mood) are more prominent in case of lower rumination, psychotic-like experiences, and somatic symptoms. Right column: Day-to-day associations between subjective sleep disruption and next day's rumination, psychotic-like experiences, and M a n u s c r i p t somatic complaints. Subjective sleep disruption as compared to the individual twoweekly averages, that is, relatively worse nights of sleep during the study period are associated with increased rumination, psychotic-like experiences, and somatic complaints the following day. Grey lines indicate the regression slopes of each individual fitted to their day-to-day reports of sleep quality and daytime experiences (individual means and slopes). The red lines show the regression slopes fitted to all data points (overall mean and slope). Points with brighter and darker colors indicate positive and negative ratings of mood respectively. As indicated by the color of the data points, more positive daily mood is associated with lower rumination, psychotic-like experiences, and somatic symptoms (See Table 2 ). M a n u s c r i p t M a n u s c r i p t Table 2 . The association of the number of deaths related to COVID-19 and of the days spent in confinement with mental health complaints, beyond the effects of age, gender, PTSD-like symptoms and cognitive disorganization. The variables reflecting the context of the pandemic are underlined, and significant associations between covid-related stressors and outcome measures are highlighted in bold. Daily reports of country-specific COVID-19 related deaths were associated with psychotic-like experiences, and somatic complaints during the day, and worse subjective sleep quality the following night. The number of global deaths predicted more somatic complaints during the day and prolonged sleep duration the following night. The time spent in confinement was inversely related to the reported levels of rumination and psychotic-like experiences and positively to sleep duration. A quadratic trend of the time spent in confinement was also observed on rumination and psychotic-like experiences, indicating that in spite of the gradual amelioration of daytime mental health complaints, prolonged time in confinement may again increase mental complaints. σ residual variance; τ variance of random intercept; τ variance of random slope; ρ correlation between random intercept and slope; ICC: intraclass correlation; N: number of participants. Marginal R 2 : variance explained by fixed effects; Conditional R 2 : variance explained by fixed and random effects. P-values were computed with Satterthwaite's approximation.

A c c e p t e d M a n u s c r i p t Table 3 . Summary of mixed models examining associations between sleep quality and subsequent daytime functioning. The day-to-day associations between sleep quality and daytime complaints are underlined. Uncorrected p-values were computed with Satterthwaite's approximation. Correction for multiple comparisons in case of the sleep-related predictors was addressed by the Benjamini-Hochberg procedure of False Discovery Rate (FDR) 66 . The significant associations between sleep and next day's mental health complaints surviving statistical correction (FDR) are highlighted in bold. σ residual variance; τ variance of random intercept; τ variance of random slope; ρ correlation between random intercept and slope; ICC: intraclass correlation; N: number of participants. Marginal R 2 : variance explained by fixed effects; Conditional R 2 : variance explained by fixed and random effects. Table 4 . Summary of mixed models examining associations between daytime functioning and subsequent (next night's) sleep quality and duration. The day-to-day associations between daytime mental health complaints and next night's sleep disruption are underlined. Uncorrected p-values were computed with Satterthwaite's approximation. None of the p-values corresponding to daytime mental health complaints remained significant after the statistical correction for multiple comparisons. From the examined measures, daytime somatic complaints predicted poorer sleep quality the following night. σ residual variance; τ variance of random intercept; τ variance of random slope; ρ correlation between random intercept and slope; ICC: intraclass correlation; N: number of participants. Marginal R 2 : variance explained by fixed effects; Conditional R 2 : variance explained by fixed and random effects.

Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. The Lancet

Coronavirus disease 2019 (COVID-19): situation report, 72

COVID-19 and mental health: A review of the existing literature

PTSD as the second tsunami of the SARS-Cov-2 pandemic

The psychological impact of quarantine and how to reduce it: rapid review of the evidence. The Lancet

Prevalence and predictors of PTSS during COVID-19 outbreak in China hardest-hit areas: Gender differences matter. Psychiatry research

Factors Associated With Mental Health Outcomes Among Health Care Workers Exposed to Coronavirus Disease

University students' mental health amidst the COVID-19 quarantine in Greece

Psychological effects of the COVID-19 outbreak and lockdown among students and workers of a Spanish university

Perceived Stress and Sleep Quality Among the Non-diseased General Public in China During the 2019 Coronavirus Disease: A Moderated Mediation Model

Immediate psychological responses and associated factors during the initial stage of the 2019 coronavirus disease (COVID-19) epidemic among the general population in China

The enemy who sealed the world: Effects quarantine due to the COVID-19 on sleep quality, anxiety, and psychological distress in the Italian population

The immediate impact of the 2019 novel coronavirus (COVID-19) outbreak on subjective sleep status

Mental Health Problems during the COVID-19 Pandemics and the Mitigation Effects of Exercise: A Longitudinal Study of College Students in China

Impact of impaired sleep on the development of PTSD symptoms in combat veterans: a prospective longitudinal cohort study

Are sleep disturbances causally linked to the presence and severity of psychotic-like, dissociative and hypomanic experiences in non-clinical populations? A systematic review

Insomnia as a predictor of depression: a meta-analytic evaluation of longitudinal epidemiological studies

Walker MP, van der Helm E. Overnight therapy? The role of sleep in emotional brain processing

Overanxious and underslept

Restless REM Sleep Impedes Overnight Amygdala Adaptation

Sleep and the processing of emotions

Dealing with sleep problems during home confinement due to the COVID-19 outbreak: Practical recommendations from a task force of the European CBT-I Academy

A comparison of prospective and retrospective assessments of sleep

Selective bias in retrospective self-reports of negative mood states

Influence of life event stress on physical illness: Substantive effects or methodological flaws?

Clinical assessment of affective instability: Comparing EMA indices, questionnaire reports, and retrospective recall

Temporal associations between sleep quality and paranoia across the paranoia continuum: An experience sampling study

Sleeping Paranoia Away? An Actigraphy and Experience-Sampling Study with Adolescents

Day-to-day variation of subjective sleep quality and emotional states among healthy university students-a 1-week prospective study

Time-Lagged Moment-to-Moment Interplay Between Negative Affect and Paranoia: New Insights in the Affective Pathway to Psychosis

Nolen-Hoeksema S, Watkins ER. A Heuristic for Developing Transdiagnostic Models of Psychopathology: Explaining Multifinality and Divergent Trajectories

The association between perseverative cognition and resting heart rate variability: A focus on state ruminative thoughts

A seven day actigraphy-based study of rumination and sleep disturbance among young adults with depressive symptoms

Co-variation between stressful events and rumination predicts depressive symptoms: An eighteen months prospective design in undergraduates

Persecutory delusions: a cognitive perspective on understanding and treatment

A systematic review and metaanalysis of the psychosis continuum: evidence for a psychosis proneness-persistence-impairment model of psychotic disorder

The role of stress-regulation genes in moderating the association of stress and daily-life psychotic experiences

Poor sleep quality predicts psychotic-like symptoms: an experience sampling study in young adults with schizotypal traits

Myin-Germeys I. Daily cortisol, stress reactivity and psychotic experiences in individuals at above average genetic risk for psychosis

Disrupting Sleep: The Effects of Sleep Loss on Psychotic Experiences Tested in an Experimental Study With Mediation Analysis

Unemployment, social isolation, achievementexpectation mismatch and psychosis: findings from the AESOP Study

Impact of distress related to attenuated psychotic symptoms in individuals at ultra high risk of psychosis: Findings from the Longitudinal Youth at Risk Study. Early Intervention in Psychiatry

Mental health characteristics associated with dysfunctional coronavirus anxiety

The PHQ-15: validity of a new measure for evaluating the severity of somatic symptoms. Psychosomatic medicine

The Association of Sleep and Pain: An Update and a Path Forward

Sleep Measures Predict Next-Day Symptoms in Women with Irritable Bowel Syndrome

Quotidian resilience: Exploring mechanisms that drive resilience from a perspective of everyday stress and coping

Resilience under conditions of extreme stress: a multilevel perspective

The network structure of schizotypy in the general population. Eur Arch Psychiatry Clin Neurosci

social stress and the emergence of psychotic-like states -A case for benign schizotypy? Schizophrenia Research

Screening Depressed Patients in Family Practice

Short scales for measuring schizotypy

The posttraumatic stress disorder checklist for DSM-5 (PCL-5): Development and initial psychometric evaluation

Subclinical Posttraumatic Stress Disorder Symptoms: Relationships with Blood Pressure, Hostility, and Sleep. Cardiovasc Psychiatry Neurol

The evaluation of the Groningen sleep quality scale. Groningen: Heymans Bulletin (HB 88-13-EX)

A questionnaire based study of subjective sleep quality: the psychometric evaluation of the Hungarian version of the Groningen Sleep Quality Scale

The psychotomimetic states inventory (PSI): measuring psychotic-type experiences from ketamine and cannabis

Fitting Linear Mixed-Effects Models Using lme4

On disaggregating between-person and within-person effects with longitudinal data using multilevel models

Controlling the False Discovery Rate: A Practical and Powerful Approach to Multiple Testing

The validity of the Beck Depression Inventory-Short Form as a screening and diagnostic instrument for moderate and severe depression in medical inpatients

Generalized anxiety disorder, depressive symptoms and sleep quality during COVID-19 outbreak in China: a web-based cross-sectional survey

Mental health during the COVID-19 pandemic in two longitudinal UK population cohorts. medRxiv

Long-term impact of earthquakes on sleep quality

Safe enough to sleep: sleep disruptions associated with trauma, posttraumatic stress, and anxiety in children and adolescents. Child and Adolescent Psychiatric Clinics of North America

Sleep disturbance as the hallmark of posttraumatic stress disorder

The role of sleep dysfunction in the occurrence of delusions and hallucinations: A systematic review

Mental health problems and social media exposure during COVID-19 outbreak

A longitudinal study on the mental health of general population during the COVID-19 epidemic in China. Brain, behavior, and immunity

Covid-19-related factors associated with sleep disturbance and suicidal thoughts among the Taiwanese public: a facebook survey

Sleep Loss and the Socio-Emotional Brain

The effect of sleep deprivation on pain perception in healthy subjects: a meta-analysis

Sleep Duration and All-Cause Mortality: A Systematic Review and Meta-Analysis of Prospective Studies

Short sleep duration and health outcomes: a systematic review, meta-analysis, and meta-regression

Impact of COVID-19 lockdown on sleep quality in university students and administration staff

Effects of sleep deprivation on cognition

Sleep complaints are associated with reduced left prefrontal activation during a verbal fluency task in patients with major depression: A multi-channel near-infrared spectroscopy study

Does the Mind Wander When the Brain Takes a Break? Local Sleep in Wakefulness, Attentional Lapses and Mind-Wandering

Sleep deprivation disrupts prepulse inhibition and induces psychosis-like symptoms in healthy humans

Combining two model systems of psychosis: The effects of schizotypy and sleep deprivation on oculomotor control and psychotomimetic states

Associations among sleep, daily experiences, and loneliness in adolescence: Evidence of moderating and bidirectional pathways

Sleep quality predicts positive and negative affect but not vice versa. An electronic diary study in depressed and healthy individuals

Who sleeps best? Longitudinal patterns and covariates of change in sleep quantity, quality, and timing across four university years

Effect of Digital Cognitive Behavioral Therapy for Insomnia on Health, Psychological Well-being, and Sleep-Related Quality of Life: A Randomized Clinical Trial

The effects of improving sleep on mental health (OASIS): a randomised controlled trial with mediation analysis

The Role of Telehealth in Reducing the Mental Health Burden from COVID-19

The authors thank Róbert Báthori who designed the user interface and layout and created the online platform for data collection.

A c c e p t e d M a n u s c r i p t