Sleep and psychotic symptoms: An actigraphy and diary study with young adults with low and elevated psychosis proneness

Impact of change in insomnia on change in pandemic paranoia: a longitudinal moderated-mediation model in an international sample

The impact of mistrust of others during a pandemic is an important consideration for public health interventions. Pandemic paranoia is a particular form of persecutory thinking characterised by mistrust and suspicion towards other people specifically due to a pandemic. Pandemic paranoia is heightened among those with a persecutory thinking tendency. We examined the longitudinal relationship between insomnia and pandemic paranoia, with anxiety, depression, and worry as mediators and persecutory thinking as moderator. A longitudinal online survey design was utilized involving an international sample (N = 715) across two timepoints, 12 weeks apart. A moderated mediation model was tested, assessing the effect of change in insomnia on change in pandemic paranoia with changes in anxiety, depression and worry as mediators. The effect of persecutory thinking as a moderator was then tested on the above paths in relation to insomnia. Changes in insomnia predicted changes in pandemic paranoia. Change in anxiety was a significant mediator of insomnia's effects on pandemic paranoia: this indirect pathway was moderated by persecutory thinking. Changes in worry and depression were not significant mediators. Our findings indicate that insomnia influences pandemic paranoia, indirectly through anxiety; persecutory thinking plays a consequential role in these relationships. These findings suggest that special attention should be given to mitigation efforts during pandemics to promote sleep health in individuals with pre-existing vulnerabilities, such as persecutory thinking styles.

The two ends of the spectrum: comparing chronic schizophrenia and premorbid latent schizotypy by actigraphy

Motor activity alterations are key symptoms of psychiatric disorders like schizophrenia. Actigraphy, a non-invasive monitoring method, shows promise in early identification. This study characterizes Positive Schizotypy Factor (PSF) and Chronic Schizophrenia (CS) groups using actigraphic data from two databases. At Hauke Land University Hospital, data from patients with chronic schizophrenia were collected; separately, at the University of Szeged, healthy university students were recruited and screened for PSF tendencies toward schizotypy. Several types of features are extracted from both datasets. Machine learning algorithms using different feature sets achieved nearly 90-95% for the CS group and 70-85% accuracy for the PSF. By applying model-explaining tools to the well-performing models, we could conclude the movement patterns and characteristics of the groups. Our study indicates that in the PSF liability phase of schizophrenia, actigraphic features related to sleep are most significant, but as the disease progresses, both sleep and daytime activity patterns are crucial. These variations might be influenced by medication effects in the CF group, reflecting the broader challenges in schizophrenia research, where the drug-free study of patients remains difficult. Further studies should explore these features in the prodromal and clinical High-Risk groups to refine our understanding of the development of the disorder.

Sleep, event appraisal, and affect: An ecological momentary assessment study

BACKGROUND

Appraisal theory posits that emotions result from cognitive appraisals of events and situations. Experimental work suggests that sleep influences cognitive processes and event appraisal, which the present study examines in real life. Poor sleep influences brain regions involved in the appraisal-to-emotion process, and tired participants showed more conservative appraisal and reported less positive and more negative affect. In the present study, we tested whether sleep duration and/or quality predicted more pleasant event appraisal and whether sleep moderated the association between event appraisal and affect.

METHODS

Participants (N = 892) from the general Dutch population reported thrice daily on event appraisal and various emotions for 30 days and once daily on sleep duration and quality. We constructed multilevel models to account for the nested structure of our data (observations within participants).

RESULTS

Multilevel regression analyses showed that on days when participants reported having slept longer and better than their average, their event appraisal was more positive. Subjective sleep duration and quality did not influence the relationship between event appraisal and affect. Hence, poor sleep predicted changes in cognitive functioning, as people appraised situations as more unpleasant.

LIMITATIONS

We measured subjective sleep duration and quality with two single items and focused on only pleasantness dimension of event appraisal.

CONCLUSIONS

Results match perspectives on emotions as multicomponent systems involving appraisal processes. Understanding the elements of event appraisal may help unravel the detrimental effects of poor sleep on mental health and well-being.

Associations between disturbed sleep and attenuated psychotic experiences in people at clinical high risk for psychosis

BACKGROUND

Pre-diagnostic stages of psychotic illnesses, including 'clinical high risk' (CHR), are marked by sleep disturbances. These sleep disturbances appear to represent a key aspect in the etiology and maintenance of psychotic disorders. We aimed to examine the relationship between self-reported sleep dysfunction and attenuated psychotic symptoms (APS) on a day-to-day basis.

METHODS

Seventy-six CHR young people completed the Experience Sampling Methodology (ESM) component of the European Union Gene-Environment Interaction Study, collected through PsyMate® devices, prompting sleep and symptom questionnaires 10 times daily for 6 days. Bayesian multilevel mixed linear regression analyses were performed on time-variant ESM data using the brms package in R. We investigated the day-to-day associations between sleep and psychotic experiences bidirectionally on an item level. Sleep items included sleep onset latency, fragmentation, and quality. Psychosis items assessed a range of perceptual, cognitive, and bizarre thought content common in the CHR population.

RESULTS

Two of the seven psychosis variables were unidirectionally predicted by previous night's number of awakenings: every unit increase in number of nightly awakenings predicted a 0.27 and 0.28 unit increase in feeling unreal or paranoid the next day, respectively. No other sleep variables credibly predicted next-day psychotic symptoms or vice-versa.

CONCLUSION

In this study, the relationship between sleep disturbance and APS appears specific to the item in question. However, some APS, including perceptual disturbances, had low levels of endorsement amongst this sample. Nonetheless, these results provide evidence for a unidirectional relationship between sleep and some APS in this population.

Schizotypy Moderates the Relationship Between Sleep Quality and Social Cognition

ABSTRACT

Poor sleep quality has been tied to worse social cognition. Social cognitive deficits have been noted in those with high schizotypy. Yet, no study has assessed whether schizotypy moderates the relationship between sleep quality and social cognition, which may be vital to our understanding of contributors to social functioning. We conducted a cross-sectional analysis of associations of sleep quality and social cognition, with potential moderation by schizotypy. Participants ( n = 906) completed self-report measures of schizotypy, sleep quality, and social cognition. Levels of schizotypy significantly moderated some of the relationships between sleep and social cognition. For participants low in total or interpersonal schizotypy, worse sleep quality was associated with worse theory of mind scores. For participants low in total, disorganized, or cognitive perceptual schizotypy, worse sleep quality was associated with worse self-reported cognitive empathy. For those high in these facets of schizotypy, worse sleep quality was associated with better self-reported cognitive empathy. These results suggest that the individual facets of schizotypy provide additional information and, therefore, are important to assess when examining social cognition and sleep.

Insomnia moderates the association between psychotic-like experiences and suicidal ideation in a non-clinical population: a network analysis

Psychotic-like experiences (PLEs) have been associated with poor sleep quality and increased suicide risk. However, the association between PLEs, insomnia and suicide risk has not been thoroughly investigated in prior studies. In this study, we aimed to explore as to whether insomnia moderates the association between PLEs and suicidal ideation. The study was performed in 4203 young adults (aged 18-35 years, 63.8% females). Data were collected using self-reports. Moderation analysis demonstrated that PLEs are associated with higher levels of the current suicidal ideation only in participants with greater severity of insomnia (B = 0.003, p < 0.001). This analysis included age, gender, education, occupation and depressive symptoms as covariates. Moreover, the network analysis demonstrated that nodes representing PLEs are connected to the node of current suicidal ideation only in participants with greater severity of insomnia. The nodes of PLEs connected to the current suicidal ideation node captured PLEs representing deja vu experiences, auditory hallucination-like experiences and paranoia (edge weights between 0.011 and 0.083). Furthermore, nodes representing PLEs were the three most central nodes in the network analysis of individuals with higher levels of insomnia (strength centrality between 0.96 and 1.10). In turn, the three most central nodes were represented by depressive symptoms in the network analysis of individuals with lower levels of insomnia (strength centrality between 0.67 and 0.79). Findings from this study indicate that insomnia might be an important risk factor of suicide in people with PLEs, especially those reporting deja vu experiences, auditory hallucination-like experiences and paranoia.

Predictors of paranoia in the daily lives of people with non-affective psychosis and non-clinical controls: A systematic review of intensive longitudinal studies

BACKGROUND AND OBJECTIVES

Worrying, self-esteem, sleep problems, anomalous internal experiences, reasoning biases, and interpersonal sensitivity are associated with paranoia. However, no review has examined whether these variables function as predictors of paranoia in everyday life. The present systematic review of intensive longitudinal studies (e.g., experience sampling) examined contemporaneous and time-lagged associations between paranoia and each candidate mechanism in individuals with non-affective psychosis and controls (pre-registration: https://osf.io/uwr9d).

METHODS

We searched electronic databases, PsyArXiv, and reference lists for studies published since 1994.

RESULTS

Of n = 5,918 results, n = 54 fulfilled inclusion criteria (n = 43 datasets). Most studies examined individuals with non-affective psychosis (n = 34). Strong evidence emerged for negative affect (subsumed under 'anomalous internal experiences') and sleep problems. For self-esteem, results suggest contemporaneous and lagged effects on paranoia but associations are likely driven by between-person variance. The low number of studies (n = 2 studies each) allowed no conclusions regarding worrying and reasoning biases. Findings on interpersonal sensitivity, which should be interpreted with caution because of the predictor's conceptual overlap with paranoia, indicate contemporaneous effects whereas time-lagged and within-person associations could not be judged due to insufficient data.

LIMITATIONS

The present review used a narrative data-synthetization and it did not cover outcomes such as hallucinations.

CONCLUSIONS

Despite convincing evidence for affect and sleep problems, it remains unclear whether affective states are precursors or also consequences of paranoia (vicious circle), and which of the actigraphy measures (sleep time, -efficiency, -fragmentation, etc.) best predicts paranoia.

The relationship between subjective sleep disturbance and attenuated psychotic symptoms after accounting for anxiety and depressive symptoms

BACKGROUND AND HYPOTHESES

Sleep disturbances are increasingly recognized as cooccurring with psychotic symptoms. The potential importance of this relationship is complicated when considering the effects of anxiety and depressive symptoms which commonly present in early-stage illness states. This study aimed to investigate the relationship between self-reported sleep disturbance on the development of attenuated psychotic symptoms (APS) cross-sectionally and longitudinally while adjusting for roles of anxiety and depressive symptoms.

DESIGN

Eight-hundred and two help-seeking young people aged 12 to 25 years who engaged with our Australian early intervention services were included in the study (the "Transitions" cohort). Cross sectional mediation and cross-lagged longitudinal (12-month) mediation models were developed with outcomes being different APS domains.

RESULTS

Only baseline excessive daytime sleepiness predicted later APS when accounting for previous APS, anxiety and depressive symptomatology. Cross sectionally, self-reported sleep disturbance showed both direct and indirect predictive relationships with all APS domains. Partial mediation through anxiety and depression was shown for unusual thought content, perceptual abnormalities, and disorganised speech, while full mediation through depression was shown for non-bizarre ideas.

CONCLUSIONS

The specificity of the relationship between self-reported sleep disturbance on APS highlights the potential for different roles in mechanistic models of psychotic symptom expression. This further indicates the need for further experimental research to illuminate potential causal pathways. Future research should continue to use continuous, symptom level approaches across a range of timeframes to more accurately model the complex dynamics present in the sleep-psychosis relationship.

Symptoms mediate the relationship between childhood trauma and non-suicidal self-injury: A hospital-based study of adolescents with mood disorder

BACKGROUND

Childhood trauma has a significant impact on the development of adolescents, which may lead to interpersonal and psychological problems. Determining the incidence and consequences of childhood trauma in psychiatric clinical practice is of great significance.

METHODS

A survey was conducted among adolescents with mood disorders. Childhood Trauma Questionnaire (CTQ), the Adolescent Non-Suicidal-Self-Injury Behavior Function Assessment Scale (ANBFAS) and a series of psychological scales were filled face to face. Path analysis was used to examine the causation structure of childhood trauma-related symptoms.

RESULTS

A total of 117 participants (74.5%) had experienced at least one type of trauma. Interpersonal and psychological features of adolescent patients with childhood trauma were detailed in this study. The path analysis model showed that the relationships between childhood trauma and NSSI were mediated by depressive symptoms and thinking disorders, respectively, whereas depressive symptoms individually mediated the correlation between childhood trauma and sleep disturbances in adolescent patients with psychiatric disorders (χ2 /df = 1.23).

CONCLUSION

For adolescent patients with childhood trauma, psychological counseling for interpersonal relationships should start with families and peers. It is important to treat their depressive symptoms and thinking disorders and alleviate NSSI behavior and sleep disorders.

The dynamic relationship between sleep and psychotic experiences across the early stages of the psychosis continuum

BACKGROUND

Psychotic disorders develop gradually along a continuum of severity. Understanding factors associated with psychosis development, such as sleep, could aid in identification of individuals at elevated risk. This study aimed to assess (1) the dynamic relationship between psychotic experiences (PEs) and sleep quality and quantity, and (2) whether this relationship differed between different clinical stages along the psychosis continuum.

METHODS

We used daily diary data (90 days) of individuals (N = 96) at early stages (i.e. before a first diagnosis of psychosis) along the psychosis continuum. Multilevel models were constructed with sleep quality and sleep quantity as predictors of PEs and vice versa. Post-hoc, we constructed a multilevel model with both sleep quality and quantity as predictors of PEs. In addition, we tested whether associations differed between clinical stages.

RESULTS

Within persons, poorer sleep predicted next day PEs (B = -0.02, p = 0.01), but not vice versa. Between persons, shorter sleep over the 90-day period predicted more PEs (B = -0.04, p = 0.002). Experiencing more PEs over 90-days predicted poorer (B = -0.02, p = 0.02) and shorter (B = -1.06, p = 0.008) sleep. We did not find any significant moderation effects for clinical stage.

CONCLUSIONS

We found a bidirectional relationship between sleep and PEs with daily fluctuations in sleep predicting next day PEs and general patterns of more PEs predicting poorer and shorter sleep. Our results highlight the importance of assessing sleep as a risk marker in the early clinical stages for psychosis.

The use of adaptive emotion regulation strategies in people with attenuated psychotic symptoms - Results from a two-week diary study

BACKGROUND

Prior research has shown that negative emotion constitutes a trigger for psychosis. This effect is further amplified by using maladaptive emotion regulation strategies. In contrast, the role of adaptive emotion regulation strategies is less clear despite its potential for informing interventions and prevention efforts. In this study, we investigated whether the decreased use of adaptive emotion regulation strategies in daily life is associated with an elevated risk of psychosis.

METHODS

Participants reporting a lifetime prevalence of attenuated psychotic symptoms (AS; n = 43) and comparison participants without attenuated psychotic symptoms (n = 40) completed a 14-day diary study with one daily assessment of adaptive emotion regulation (ER) strategies ranging from tolerance-based ER-strategies (e.g., understanding, constructively directing attention) to change-focused ER-strategies (e.g., modification, effective self-support). We tested for group differences in adaptive ER-strategies use with multilevel models.

RESULTS

AS used multiple tolerance-based adaptive ER-strategies (acceptance, understanding, clarity, directing attention) less frequently in daily life. However, only a single change-focused adaptive ER-strategy (modification) showed consistently lower utilization rates in AS.

CONCLUSION

People with an elevated risk of psychosis use various adaptive ER-strategies focusing on comprehending and accepting negative emotions less frequently. Fostering these strategies with targeted interventions could promote resilience against transitioning into psychosis.

The longitudinal relationship between sleep length and psychotic-like experiences in adolescents

The longitudinal relationship between psychotic-like experiences (PLEs) and short habitual sleep in adolescents remains to be investigated. We examined the effect of habitual sleep length (time-in-bed: TIB) on the risk of subsequent year PLEs and vice versa, in grade 7-12 students (ages: 12-18, n = 1,685) followed over 6 years. Yearly longitudinal data were analyzed using cross-lagged panel models. Shorter weekday TIB was associated with a higher risk of subsequent year PLEs; PLEs did not affect subsequent year TIB. Compared to a TIB of 8-9 h, 5-6 h increased PLEs likelihood 1.8 times; <5 h increased this 6-fold.

Experimental Sleep Deprivation Results in Diminished Perceptual Stability Independently of Psychosis Proneness

Psychotic disorders as well as psychosis proneness in the general population have been associated with perceptual instability, suggesting weakened predictive processing. Sleep disturbances play a prominent role in psychosis and schizophrenia, but it is unclear whether perceptual stability diminishes with sleep deprivation, and whether the effects of sleep deprivation differ as a function of psychosis proneness. In the current study, we aimed to clarify this matter. In this preregistered study, 146 participants successfully completed an intermittent version of the random dot kinematogram (RDK) task and the 21-item Peters Delusion Inventory (PDI-21) to assess perceptual stability and psychosis proneness, respectively. Participants were randomized to sleep either as normal (8 to 9 h in bed) (n = 72; Mage = 24.7, SD = 6.2, 41 women) or to stay awake through the night (n = 74; Mage = 24.8, SD = 5.1, 44 women). Sleep deprivation resulted in diminished perceptual stability, as well as in decreases in perceptual stability over the course of the task. However, we did not observe any association between perceptual stability and PDI-21 scores, nor a tendency for individuals with higher PDI-21 scores to be more vulnerable to sleep-deprivation-induced decreases in perceptual stability. The present study suggests a compromised predictive processing system in the brain after sleep deprivation, but variation in psychosis trait is not related to greater vulnerability to sleep deprivation in our dataset. Further studies in risk groups and patients with psychosis are needed to evaluate whether sleep loss plays a role in the occurrence of objectively measured perceptual-related clinical symptoms.

The temporal dynamics of sleep disturbance and psychopathology in psychosis: a digital sampling study

BACKGROUND

Sleep disruption is a common precursor to deterioration and relapse in people living with psychotic disorders. Understanding the temporal relationship between sleep and psychopathology is important for identifying and developing interventions which target key variables that contribute to relapse.

METHODS

We used a purpose-built digital platform to sample self-reported sleep and psychopathology variables over 1 year, in 36 individuals with schizophrenia. Once-daily measures of sleep duration and sleep quality, and fluctuations in psychopathology (positive and negative affect, cognition and psychotic symptoms) were captured. We examined the temporal relationship between these variables using the Differential Time-Varying Effect (DTVEM) hybrid exploratory-confirmatory model.

RESULTS

Poorer sleep quality and shorter sleep duration maximally predicted deterioration in psychosis symptoms over the subsequent 1-8 and 1-12 days, respectively. These relationships were also mediated by negative affect and cognitive symptoms. Psychopathology variables also predicted sleep quality, but not sleep duration, and the effect sizes were smaller and of shorter lag duration.

CONCLUSIONS

Reduced sleep duration and poorer sleep quality anticipate the exacerbation of psychotic symptoms by approximately 1-2 weeks, and negative affect and cognitive symptoms mediate this relationship. We also observed a reciprocal relationship that was of shorter duration and smaller magnitude. Sleep disturbance may play a causal role in symptom exacerbation and relapse, and represents an important and tractable target for intervention. It warrants greater attention as an early warning sign of deterioration, and low-burden, user-friendly digital tools may play a role in its early detection.

The nature, consequences, mechanisms, and management of sleep disturbances in individuals at-risk for psychosis

There is strong evidence that sleep disturbances are commonly experienced by people with psychosis. Evidence has also shown that sleep disturbances are present since the very early stages of the disease, even during the pre-diagnostic phase. More recently, research involving young individuals at ultra-high risk (UHR) for psychosis documented frequent occurrence of sleep disturbances in this group. The very early onset of sleep disturbances in the course of psychosis has drawn attention to the possible links between sleep parameters and the risk of psychosis. To date, the nature of sleep disturbances characterizing the UHR stage remains unclear, with available studies having yielded mixed findings. In this regard, we performed this review to update the body of literature on the nature of sleep disturbances, their underlying mechanisms, their clinical and functional consequences, the prevention and intervention strategies in the at-risk for psychosis population. Our findings provided further support to the presence of disturbed sleep in UHR individuals as evidenced by subjective and objective sleep measures such as polysomnography, sleep electroencephalograms, and actigraphy. Reviewing the possible mechanisms underlying the relationship between sleep and psychosis emphasized its complex and multifactorial nature which is yet to be determined and understood. Further research is warranted to determine which facets of sleep disturbances are most detrimental to this specific population, and to what extent they can be causal factors or markers of psychosis.

Schizotypy unfolding into the night? Schizotypal traits and daytime psychotic-like experiences predict negative and salient dreams

Symptoms of insomnia and frequent nightmares are prevalent in psychotic disorders, and are associated with psychotic-like experiences (PLEs) in the non-clinical population. Whereas the role of impaired sleep in psychosis was extensively examined by longitudinal and interventional approaches, studies on the association between psychosis and dream quality are scarce, and mainly cross-sectional. We conducted a three-week long prospective study in a group of healthy adults (N = 55), assessed schizotypal traits, daily PLEs, and the emotional quality of dreams recalled in the morning (N = 490). We extracted the latent factors of schizotypal traits and dream emotions, and examined the predictive value of trait-and state-like variables on day-to-day reports of PLEs and dream quality. PLEs reported in the evening predicted emotionally more negative and salient dream reports the following morning. On the other hand, the quality of dreams were not predictive of PLEs reported later during the day. Schizotypal personality traits were differentially associated with dream quality: Introvertive Anhedonia, Cognitive Disorganization, and General-Disorganized schizotypy were linked to more negative dream valence, whereas Unusual Experiences were associated with more salient dreams. Our findings highlight the relevance of the multidimensional nature of schizotypal traits, the role of different facets of schizotypy in daytime and nocturnal mental experiences, and the day-to-day associations between PLEs and dream affect. GENERAL SCIENTIFIC SUMMARIES (GSS): The aim of the study was to examine the temporal associations between psychotic-like experiences and dream emotions, taking into account the trait factors of schizotypy. Psychotic-like experiences during the evening hours predicted reporting more negative and salient dreams the following morning, and schizotypal personality traits were differentially associated with the dimensions of dream emotions.

The relationship between stress responding in family context and stress sensitivity with sleep dysfunction in individuals at clinical high-risk for psychosis

Stress and sleep have been implicated in the etiology of psychosis, and literature suggests they are closely related. Two distinct domains of stress associated with sleep dysfunction in the general population are responsivity to environmental stressors and stress sensitivity. However, to date, no research has examined relationships between these stress domains and sleep dysfunction in individuals at clinical high-risk (CHR) for psychosis. A total of 57 CHR (mean age = 18.89, SD = 1.82) and 61 healthy control (HC; mean age = 18.34, SD = 2.41) adolescents and young adults completed a measure of emerging stress intolerance. A subset of participants (CHR = 50, HC = 49) completed a measure indexing responsivity to family stressors - an integral context for this developmental stage overlapping with the psychosis-risk period. Sleep efficiency, continuity, and duration were objectively assessed by actigraphy (CHR = 38, HC = 36). Partial correlations with age and sex as covariates were conducted in both groups separately to examine relationships between stress and sleep. Results indicated that automatic maladaptive responsivity to family stressors was associated with disrupted sleep in the CHR but not HC group. Specifically, greater involuntary engagement was associated with poorer sleep efficiency (r = -.42) but not sleep continuity (r = 0.31) and duration (r = .-19). Interestingly, both adaptative and maladaptive voluntary responses to stressors (engagement and disengagement coping) were not associated with sleep. Finally, impaired stress tolerance was associated with sleep efficiency (r = -0.47), continuity (r = 0.37), and duration (r = -0.43). Taken together, findings provided important groundwork for understanding the role of the relationship between involuntary maladaptive responsivity to family stressors and stress sensitivity with sleep in psychosis etiology.

Comparison of actigraphy indices among patients with depression and schizophrenia: A preliminary study

Background:

Schizophrenia (SCZ) and depression (MDD) are associated with changes in sleep and activity patterns. However, because of a lack of objective evaluation, the diagnostic or clinical value of these sleep-activity patterns is unknown. In this study, we attempted to assess and compare the sleep and activity patterns using actigraphy.

Materials and Methods:

We have recruited 35 patients with SCZ (mean age: 29.29 ± 7.54 years) and 42 patients with MDD (mean age: 27.5 ± 5.59 years) in this cross-sectional study. The actigraphy indices [Time in bed (minutes), Onset latency (minutes), Total sleep time (Minutes), Sleep efficiency (%), WASO (minutes), number of awakening, and activity duration (minutes) were compared among the two groups using unpaired t-test and Fisher exact test.

Results:

In the MDD group, the time in bed (minutes) was significantly higher than in the SCZ group (402.7 ± 41.97 vs. 379.1 ± 40.45, P = 0.01), while the sleep efficiency was lower in the SCZ group than in the MDD group (60.04 ± 9.25 vs. 65.05 ± 7.16, P = 0.0092). An increase in onset latency (minutes) was observed in the SCZ group compared to the MDD group (49.06 ± 16.09 vs. 43.6 ± 10.14, P = 0.074). The difference in WASO (minutes), the number of awakenings, and activity duration (minutes) among the two groups were insignificant.

Conclusion:

Actigraphy parameters such as sleep efficiency and time in bed may be a useful sleep process, etiological, and prognostic markers in patients with SCZ and MDD. The longitudinal studies are needed to estimate the predictive role of these parameters for therapeutic outcome in these patients.

Sleep Disturbance in Individuals at Clinical High Risk for Psychosis

INTRODUCTION

Disturbed sleep is a common feature of psychotic disorders that is also present in the clinical high risk (CHR) state. Evidence suggests a potential role of sleep disturbance in symptom progression, yet the interrelationship between sleep and CHR symptoms remains to be determined. To address this knowledge gap, we examined the association between disturbed sleep and CHR symptoms over time.

METHODS

Data were obtained from the North American Prodrome Longitudinal Study (NAPLS)-3 consortium, including 688 CHR individuals and 94 controls (mean age 18.25, 46% female) for whom sleep was tracked prospectively for 8 months. We used Cox regression analyses to investigate whether sleep disturbances predicted conversion to psychosis up to >2 years later. With regressions and cross-lagged panel models, we analyzed longitudinal and bidirectional associations between sleep (the Pittsburgh Sleep Quality Index in conjunction with additional sleep items) and CHR symptoms. We also investigated the independent contribution of individual sleep characteristics on CHR symptom domains separately and explored whether cognitive impairments, stress, depression, and psychotropic medication affected the associations.

RESULTS

Disturbed sleep at baseline did not predict conversion to psychosis. However, sleep disturbance was strongly correlated with heightened CHR symptoms over time. Depression accounted for half of the association between sleep and symptoms. Importantly, sleep was a significant predictor of CHR symptoms but not vice versa, although bidirectional effect sizes were similar.

DISCUSSION

The critical role of sleep disturbance in CHR symptom changes suggests that sleep may be a promising intervention target to moderate outcome in the CHR state.

"Assessing the Psychometric Properties of the PROMIS Sleep Measures in Persons with Psychosis."

An accumulation of research has indicated that persons with psychotic disorders experience a variety of sleep disturbances. However, few studies have examined the psychometric properties of sleep assessments that are utilized in this population. We conducted two studies to examine the reliability and validity of the PROMISTM Sleep Disturbance and Sleep-Related Impairment scales in outpatient samples of persons with psychosis. In Study 1, we examined the internal consistency and convergent validity of the PROMIS sleep scales in individuals with various psychotic disorders (N = 98) and healthy controls (N = 22). The PROMIS sleep scales showed acceptable internal consistency and convergent validity in both healthy controls and individuals with psychotic disorders. In addition, replicating prior research, the PROMIS scales identified greater sleep disturbance and sleep-related impairment in participants with psychotic disorders compared to healthy controls. In Study 2, we examined the test-retest reliability (M = 358 days) of the PROMIS sleep scales in a subset (N = 37) of persons with psychotic disorders who previously participated in Study 1. We also assessed the relation between these self-report measures and actigraph sleep parameters. The results showed that PROMIS sleep measures demonstrated modest temporal stability in the current sample. Contrary to our hypothesis, there was a lack of correspondence between these scales and actigraph sleep parameters. Overall, these findings indicate that the PROMIS sleep scales are psychometrically sound measures for populations with psychosis and highlight the importance of utilizing a multi-method approach to assess sleep.

Long and short sleep duration and psychotic symptoms in adolescents: Findings from a cross-sectional survey of 15 786 Japanese students

Sleep problems during adolescence affect current and subsequent mental health and are associated with experiences of psychotic symptoms. Recent studies have suggested that short sleep duration increases the risk of experiencing psychotic symptoms in the general adolescent population; however, whether long sleep duration is associated with an increased risk of psychotic symptoms in adolescence remains unclear. The present study aimed to examine the relationships between long sleep duration, short sleep duration, and the risk of experiencing psychotic symptoms in adolescence. Cross-sectional survey data from 15,786 junior and senior high school students (12- to 15-year-olds and 15- to 18-year-olds, respectively) in Japan were collected and analyzed using logistic regression analysis after controlling for covariates, including depressive symptoms. Long sleep duration was associated with a 1.6- to 2.8-fold increased risk of psychotic symptoms in male but not in female adolescents. Short sleep duration was also related with a 1.6- to 2.9-fold increased risk of experiencing psychotic symptoms, except for 15- to 18-year-old female adolescents. The present study suggested that adolescents with long and short sleep duration should be assessed for their risk of experiencing psychotic symptoms regardless of concurrent depressive symptoms.