Sleep problems and attenuated psychotic symptoms in youth at clinical high-risk for psychosis

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.

Sleep Problems, Suicidal Ideation, and Psychopathology in First-Episode Psychosis

BACKGROUND AND HYPOTHESIS

Insomnia occurs frequently in the clinical course of schizophrenia. A growing literature has found associations between insomnia, suicidal ideation and behavior, and psychopathology in schizophrenia. We explored associations between sleep problems, suicidal ideation, and psychopathology in a cohort of patients with first-episode psychosis.

STUDY DESIGN

We performed a secondary analysis of data for n = 403 subjects with data from the Recovery After an Initial Schizophrenia Episode study using regression models.

STUDY RESULTS

The prevalence of sleep problems and suicidal ideation at baseline was 57% and 15%, respectively. After controlling for potential confounders, in the study baseline sleep problems were associated with increased odds of suicidal ideation with evidence of a dose-dependent relationship (OR = 2.25, 95% CI 1.15-4.41, P = .018). Over 24 months, sleep problems at any time point were associated with an over 3-fold increased odds of concurrent suicidal ideation (OR = 3.21, 95% CI 1.45-7.14, P = .004). Subjects with persistent sleep problems were almost 14 times more likely to endorse suicidal ideation at least once over the study than those without sleep problems (OR = 13.8, 95% CI 6.5-53.4, P < .001). Sleep problems were also a predictor of higher Positive and Negative Syndrome Scale total (β = 0.13-0.22), positive (β = 0.14-0.25), and general (β = 0.16-0.27) subscale scores at baseline and multiple follow-up visits (P < .01 for each).

CONCLUSIONS

Sleep problems are highly prevalent and associated with suicidal ideation and greater psychopathology in first-episode psychosis. Formal assessment and treatment of insomnia appear relevant to the clinical care of patients with psychosis as a predictor of suicidal ideation and symptom severity.

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.

The reliability and validity of the revised Green et al. paranoid thoughts scale in individuals at clinical high-risk for psychosis

INTRODUCTION

Paranoia is a common and impairing psychosis symptom, which exists along a severity continuum that extends into the general population. Individuals at clinical high-risk for psychosis (CHR) frequently experience paranoia and this may elevate their risk for developing full psychosis. Nonetheless, limited work has examined the efficient measurement of paranoia in CHR individuals. The present study aimed to validate an often-used self-report measure, the revised green paranoid thoughts scale (RGPTS), in this critical population.

METHOD

Participants were CHR individuals (n = 103), mixed clinical controls (n = 80), and healthy controls (n = 71) who completed self-report and interview measures. Confirmatory factor analysis (CFA), psychometric indices, group differences, and relations to external measures were used to evaluate the reliability and validity of the RGPTS.

RESULTS

CFA replicated a two-factor structure for the RGPTS and the associated reference and persecution scales were reliable. CHR individuals scored significantly higher on both reference and persecution, relative to both healthy (ds = 1.03, 0.86) and clinical controls (ds = 0.64, 0.73). In CHR participants, correlations between reference and persecution and external measures were smaller than expected, though showed evidence of discriminant validity (e.g., interviewer-rated paranoia, r = 0.24). When examined in the full sample, correlation magnitude was larger and follow-up analyses indicated that reference related most specifically to paranoia (β = 0.32), whereas persecution uniquely related to poor social functioning (β = -0.29).

CONCLUSION

These results demonstrate the reliability and validity of the RGPTS, though its scales related more weakly to severity in CHR individuals. The RGPTS may be useful in future work aiming to develop symptom-specific models of emerging paranoia in CHR individuals.

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.

Sleep Disturbances in At-Risk Mental States and First Episode of Psychosis: A Narrative Review on Interventions

Sleep disturbances are a common yet often overlooked symptom of psychosis that can drastically affect the quality of life and well-being of those living with the condition. Sleep disorders are common in people diagnosed with schizophrenia and have significant negative effects on the clinical course of the illness and the functional outcomes and quality of life of patients. There is a limited number of studies addressing this question in first-episode psychosis (FEP). In this narrative review, we aimed to provide an overview of sleep disorders in populations with FEP and at-risk mental states (ARMS). The review was focused on the various treatments currently used for sleep disorders, including both non-pharmacological and pharmacological treatments. A total of 48 studies were included. We found that sleep disturbances are associated with attenuated psychotic symptoms and other psychopathological symptoms in ARMSs. The association of sleep disturbances with the transition to psychosis has been poorly investigated. Sleep disturbances have an impact on the quality of life and the psychopathological symptoms of people suffering from FEP. The non-pharmacological treatments include cognitive behavioral therapy for insomnia, bright light therapy, cognitive restructuring techniques, sleep restriction therapy, basic sleep hygiene education, and the provision of portable sleep trackers. Other treatments include antipsychotics in acute phases and melatonin. The early intervention in sleep disturbances may improve overall prognosis in emerging psychosis populations.

Copy number variation at the 22q11.2 locus influences prevalence, severity, and psychiatric impact of sleep disturbance

BACKGROUND

Sleep disturbance is common, impairing, and may affect symptomatology in developmental neuropsychiatric disorders. Here, we take a genetics-first approach to study the complex role of sleep in psychopathology. Specifically, we examine severity of sleep disturbance in individuals with a reciprocal copy number variant (CNV) at the 22q11.2 locus and determine sleep's effect on psychiatric symptoms. CNVs (deletion or duplication) at this locus confer some of the greatest known risks of neuropsychiatric disorders; recent studies suggest the 22q11.2 deletion negatively impacts sleep, but sleep disruption associated with 22q11.2 duplication has not been investigated.

METHODS

We compared subjective sleep disturbance and its relationship to psychiatric symptoms cross-sectionally and longitudinally over 1 year in 107 22q11.2 deletion (22qDel) carriers (14.56±8.0 years; 50% male), 42 22q11.2 duplication (22qDup) carriers (16.26±13.1 years; 54.8% male), and 88 age- and sex-matched controls (14.65±7.4 years; 47.1% male). Linear mixed models were used to compare sleep disturbance, assessed via the Structured Interview for Psychosis-Risk Syndromes (SIPS), across groups. Next, CNV carriers were categorized as good or poor sleepers to investigate sleep effects on multiple neurobehavioral traits: psychosis-risk symptoms (SIPS), autism-related behaviors (Repetitive Behavior Scale (RBS) and Social Responsiveness Scale (SRS)), real-world executive function (Behavior Rating Inventory of Executive Function (BRIEF)), and emotional/behavioral problems (Child Behavior Checklist (CBCL)). Linear mixed models tested the effect of sleep category and a group-by-sleep interaction on each measure, cross-sectionally and longitudinally.

RESULTS

22qDel and 22qDup carriers both reported poorer sleep than controls, but did not differ from each other. Cross-sectionally and longitudinally, poor sleepers scored higher on positive symptoms, anxious/depressed, somatic complaints, thought problems, and aggressive behavior, as well as RBS and SRS total scores. There were significant group-by-sleep interactions for positive symptoms and the majority of CBCL subdomains, in which the difference between good and poor sleepers was larger in 22qDel compared to 22qDup.

CONCLUSIONS

Our findings indicate that CNVs at the 22q11.2 locus impact sleep which, in turn, influences psychopathology. Sleep disturbances can differentially impact psychopathology, depending on 22q11.2 gene dosage. Our findings serve as a starting point for exploring a genetic basis for sleep disturbance in developmental neuropsychiatric disorders.

No rest for the weary: Prevalence, impact and nature of sleep problems among young people at risk of psychosis

AIMS

Sleep problems are common in people with a psychosis-spectrum diagnosis and are associated with worse psychotic symptoms and lower quality of life. Sleep problems are also frequent in individuals at a clinical high risk for psychosis (CHR-P) however, less is known about the prevalence and association with symptoms in this population. This study investigates the prevalence of sleep problems within CHR-P individuals and the associations with attenuated positive symptoms, transition to psychosis, time to transition to psychosis and functioning.

METHODS

The clinical records interactive search (CRIS) tool was used to carry out a retrospective study of 795 CHR-P individuals. Sleep problems, subsequent psychotic diagnoses, attenuated positive symptoms and Health of The Nation Outcome Scale scores were extracted. Regression models were used to examine the association between sleep problems and clinical outcomes.

RESULTS

59.5% of CHR-P individuals experienced sleep problems. Perceptual abnormality severity (OR = 1.24, 95% CI = 1.05-1.48) and frequency (OR = 1.31, 95% CI = 1.08-1.58) as measured by the Comprehensive Assessment of At-Risk Mental State interview, predicted sleep problems. Sleep problems were not associated with transition to psychosis; however, they were significantly associated with a shorter time to transition in individuals who developed psychosis (HR = 1.4, 95% CI = 1.05-1.88) and higher follow-up Health of the Nation Outcome Scale scores (MD = 2.26, 95% CI = 0.55-3.96).

CONCLUSIONS

The high prevalence of sleep problems, along with the association with positive symptoms and worse functioning, highlights the need for effective sleep interventions in this population. Further research is needed to better understand the relationship between sleep problems and transition to psychosis.

Neurobehavioral Dimensions of Prader Willi Syndrome: Relationships Between Sleep and Psychosis-Risk Symptoms

Background

Prader Willi Syndrome (PWS) is a genetic disorder caused by the absence of expression of the paternal copies of maternally imprinted gene(s) located at 15q11-q13. While the physical and medical characteristics of PWS, including short stature, hyperphagia and endocrine dysfunction are well-characterized, systematic investigation of the long-recognized psychiatric manifestations has been recent.

Methods

Here, we report on the first remote (web-based) assessment of neurobehavioral traits, including psychosis-risk symptoms (Prodromal Questionnaire-Brief Version; PQ-B) and sleep behaviors (Pittsburgh Sleep Quality Index), in a cohort of 128 participants with PWS, of whom 48% had a paternal deletion, 36% uniparental disomy, 2.4% an imprinting mutation and 13% unknown mutation (mean age 19.3 years ± 8.4; 53.9% female). We aimed to identify the most informative variables that contribute to psychosis-risk symptoms. Multiple domains of cognition (accuracy and speed) were also assessed in a subset of PWS participants (n = 39) using the Penn Computerized Neurocognitive Battery (Penn-CNB).

Results

Individuals with PWS reported a range of psychosis-risk symptoms, with over half reporting cognitive disorganization (63.1%) and about one third reporting unusual beliefs (38.6%) and/or suspiciousness (33.3%). Subjectively-reported sleep quality, nap frequency, sleep duration, sleep disturbance, and daytime dysfunction were significant predictors of psychosis-risk symptom frequency and severity (all p's < 0.029). Sleep disturbance ratings were the strongest predictors of psychosis-risk symptoms. Regarding cognition, individuals with PWS showed the most prominent deficits in accuracy on measures of social cognition involving faces, namely Face Memory, Age Differentiation and Emotion Recognition, and greatest slowing on measures of Attention and Emotion Recognition. However, there were no significant differences in psychosis-risk symptoms or cognitive performance as a function of PWS genetic subtype.

Conclusions

PWS is associated with a high prevalence of distressing psychosis-risk symptoms, which are associated with sleep disturbance. Findings indicate that self/parent-reported neurobehavioral symptoms and cognition can be assessed remotely in individuals with PWS, which has implications for future large-scale investigations of rare neurogenetic disorders.

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.

Sleep Abnormalities in Schizophrenia: State of the Art and Next Steps

Sleep disturbances are commonly observed in schizophrenia, including in chronic, early-course, and first-episode patients. This has generated considerable interest, both in clinical and research endeavors, in characterizing the relationship between disturbed sleep and schizophrenia. Sleep features can be objectively assessed with EEG recordings. Traditionally, EEG studies have focused on sleep architecture, which includes non-REM and REM sleep stages. More recently, numerous studies have investigated alterations in sleep-specific rhythms, including EEG oscillations, such as sleep spindles and slow waves, in individuals with schizophrenia compared with control subjects. In this article, the author reviews state-of-the-art evidence of disturbed sleep in schizophrenia, starting from the relationship between sleep disturbances and clinical symptoms. First, the author presents studies demonstrating abnormalities in sleep architecture and sleep-oscillatory rhythms in schizophrenia and related psychotic disorders, with an emphasis on recent work demonstrating sleep spindles and slow-wave deficits in early-course and first-episode schizophrenia. Next, the author shows how these sleep abnormalities relate to the cognitive impairments in patients diagnosed with schizophrenia and point to dysfunctions in underlying thalamocortical circuits, Ca+ channel activity, and GABA-glutamate neurotransmission. Finally, the author discusses some of the next steps needed to further establish the role of altered sleep in schizophrenia, including the need to investigate sleep abnormalities across the psychotic spectrum and to establish their relationship with circadian disturbances, which in turn will contribute to the development of novel sleep-informed treatment interventions.

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.

Sleep abnormalities in individuals at clinical high risk for psychosis

Youth at clinical high risk (CHR) represent a unique population enriched for precursors of major psychiatric disorders. Sleep disturbances are consistently reported in CHR individuals. However, there is a dearth of studies investigating quantifiable objective measures of sleep dysfunction in CHR youth. In this study, sleep high density (hd)-EEG recordings were collected in twenty-two CHR and twenty healthy control (HC) subjects. Sleep architecture parameters, as well as sleep EEG power spectra in five frequency bands, were computed and compared between CHR and HC groups during non-rapid eye movement (NREM) sleep. Furthermore, correlation analyses between sleep EEG power spectra, sleep architecture parameters, and clinical symptoms, assessed with the scale of prodromal symptoms (SOPS), were conducted in CHR participants. Our results show that CHR individuals had more wakefulness after sleep onset (WASO) compared to HC participants. CHR also showed a higher NREM sleep gamma EEG power, which was observed in a large fronto-parieto-occipital area, relative to HC. Additionally, higher NREM gamma activity in lateral fronto-occipital regions was associated with more WASO, and increased NREM gamma power in medial fronto/parietal areas correlated with worse SOPS negative symptoms. Altogether, these findings suggest that topographically specific increases in EEG gamma activity during NREM sleep represent neurophysiological signatures underlying some of the objectively assessed sleep disturbances and clinical symptoms of CHR individuals.

The association between sleep disturbances and negative symptom severity in patients with non-affective psychotic disorders, unaffected siblings and healthy controls

Sleep disturbances in patients with psychotic disorders are common and associated with poor clinical outcomes, but research on negative symptoms is limited. This study aimed to examine the association between subjective sleep disturbances and negative symptoms in 525 patients with non-affective psychotic disorders, 569 unaffected siblings and 265 healthy controls (HC) from the Genetic Risk and Outcome of Psychosis (GROUP) study. Several aspects of subjective sleep disturbances were assessed: sleep satisfaction, sleep onset insomnia, midnocturnal insomnia, early morning insomnia, and hypersomnia. Regression analyses revealed significant negative associations between sleep satisfaction and negative symptoms in all three groups. In addition, significant associations with sleep onset insomnia and hypersomnia were found in patients and with early morning insomnia and hypersomnia in siblings. Exploratory mediation analyses showed that depressive symptoms partly mediated all associations on the subclinical level in siblings and healthy controls, whereas only the association with sleep onset insomnia was mediated in patients. The results of this study implicate specific sleep disturbances and depressive symptoms as potential targets in prevention or intervention strategies focussed on negative symptoms in individuals suffering from, or at risk of non-affective psychotic disorders.

Sleep disturbances and the At Risk Mental State: A systematic review and meta-analysis

AIMS

To synthesise and investigate how sleep disturbances relate to psychotic symptoms, functioning and Quality of Life (QoL) in At Risk Mental State (ARMS) youth.

METHOD

A comprehensive search of six databases (MEDLINE, PsycINFO, Embase, CINAHL, Web of Science and CENTRAL) was conducted. Eligible studies provided data on sleep disturbances or disorders in ARMS patients.

RESULTS

Sixteen studies met the inclusion criteria (n = 1962 ARMS patients) including 7 cross-sectional studies, 2 RCT's and 7 cohort studies. Narrative synthesis revealed that self-reported sleep (e.g., general disturbances, fragmented night time sleep and nightmares) was poorer among ARMS patients compared to healthy controls. In the limited studies (n = 4) including objective measurements of sleep disturbances, ARMS patients experienced higher levels of movement during sleep, more daytime naps and increased sleep latency compared to controls. Furthermore, sleep disturbances were associated with attenuated psychotic symptoms and functional outcomes cross-sectionally and longitudinally. Only one study investigated the relationship between sleep and QoL. The exploratory meta-analysis revealed a significant difference in self-reported sleep disturbances measured by the PSQI (mean difference in score: 3.30 (95% CI 1.87, 4.74), p < 0.00001) and SIPS (mean difference in score: 1.58 (95% CI 0.80, 2.35), p < 0.00001) of ARMS patients compared to control groups.

CONCLUSIONS

ARMS individuals report impaired sleep quality and reduced sleep quantity compared to healthy controls. However, further research is needed to explore the longitudinal relationship between sleep disruptions and QoL in early psychosis. Significant variations in how sleep is measured across studies highlight a need to assess disturbances to sleep using robust and consistent approaches in this patient group.

Prediction and Prevention in the Clinical High-Risk for Psychosis Paradigm: A Review of the Current Status and Recommendations for Future Directions of Inquiry

Prediction and prevention of negative clinical and functional outcomes represent the two primary objectives of research conducted within the clinical high-risk for psychosis (CHR-P) paradigm. Several multivariable "risk calculator" models have been developed to predict the likelihood of developing psychosis, although these models have not been translated to clinical use. Overall, less progress has been made in developing effective interventions. In this paper, we review the existing literature on both prediction and prevention in the CHR-P paradigm and, primarily, outline ways in which expanding and combining these paths of inquiry could lead to a greater improvement in individual outcomes for those most at risk.

Treating sleep problems in young people at ultra-high-risk of psychosis: study protocol for a single-blind parallel group randomised controlled feasibility trial (SleepWell)

BACKGROUND

Effective interventions, targeting key contributory causal factors, are needed to prevent the emergence of severe mental health problems in young people. Insomnia is a common clinical issue that is problematic in its own right but that also leads to the development and persistence of psychotic experiences. The implication is that treating sleep problems may prevent the onset of psychosis. We collected initial case series data with 12 young people at ultra-high-risk of psychosis. Post-intervention, there were improvements in sleep, depression and psychotic experiences. Now we test the feasibility of a randomised controlled trial, with a clinical aim to treat sleep problems and hence reduce depression, psychotic experiences, and prevent transition to psychosis.

METHODS AND ANALYSIS

A randomised controlled feasibility trial will be conducted. Forty patients aged 14 to 25 years who are at ultra-high-risk of psychosis and have sleep disturbance will be recruited from National Health Service (NHS) mental health services. Participants will be randomised to receive either a novel, targeted, youth-focussed sleep intervention in addition to usual care or usual care alone. Assessor-blinded assessments will be conducted at baseline, 3 months (post-intervention) and 9 months (follow-up). The eight-session psychological intervention will target the key mechanisms which disrupt sleep: circadian rhythm irregularities, low sleep pressure, and hyperarousal. To gain an in-depth understanding of participants' views on the acceptability of the intervention and study procedures, 16 participants (n=10 intervention, n=6 control) will take part in qualitative interviews. Analyses will focus on feasibility outcomes (recruitment, retention, and treatment uptake rates) and provide initial CI estimates of intervention effects. Thematic analysis of the qualitative interviews will assess the acceptability of the intervention and trial procedures.

ETHICS AND DISSEMINATION

The trial has received ethical approval from the NHS Health Research Authority. Findings will be disseminated through peer-reviewed publications, conference presentations, and lay networks.

TRIAL REGISTRATION NUMBER

ISRCTN85601537.

Sleep Disturbances in Patients with Persistent Delusions: Prevalence, Clinical Associations, and Therapeutic Strategies

Sleep disturbances accompany almost all mental illnesses, either because sound sleep and mental well-being share similar requisites, or because mental problems lead to sleep problems, or vice versa. The aim of this narrative review was to examine sleep in patients with delusions, particularly in those diagnosed with delusional disorder. We did this in sequence, first for psychiatric illness in general, then for psychotic illnesses where delusions are prevalent symptoms, and then for delusional disorder. The review also looked at the effect on sleep parameters of individual symptoms commonly seen in delusional disorder (paranoia, cognitive distortions, suicidal thoughts) and searched the evidence base for indications of antipsychotic drug effects on sleep. It subsequently evaluated the influence of sleep therapies on psychotic symptoms, particularly delusions. The review’s findings are clinically important. Delusional symptoms and sleep quality influence one another reciprocally. Effective treatment of sleep problems is of potential benefit to patients with persistent delusions, but may be difficult to implement in the absence of an established therapeutic relationship and an appropriate pharmacologic regimen. As one symptom can aggravate another, comorbidities in patients with serious mental illness all need to be treated, a task that requires close liaison among medical specialties.

Sleep and schizophrenia: From epiphenomenon to treatable causal target

BACKGROUND

Sleep disturbance is a common clinical issue for patients with psychosis. It has been identified as a putative causal factor in the onset and persistence of psychotic experiences (paranoia and hallucinations). Hence sleep disruption may be a potential treatment target to prevent the onset of psychosis and reduce persistent psychotic experiences. The aim of this review is to describe developments in understanding the nature, causal role, and treatment of sleep disruption in psychosis.

METHOD

A systematic literature search was conducted to identify studies, published in the last five years, investigating subjective sleep disruption and psychotic experiences.

RESULTS

Fifty-eight papers were identified: 37 clinical and 21 non-clinical studies. The studies were correlational (n = 38; 20 clinical, 18 non-clinical), treatment (n = 7; 1 non-clinical), qualitative accounts (n = 6 clinical), prevalence estimates (n = 5 clinical), and experimental tests (n = 2 non-clinical). Insomnia (50%) and nightmare disorder (48%) are the most prevalent sleep problems found in patients. Sleep disruption predicts the onset and persistence of psychotic experiences such as paranoia and hallucinations, with negative affect identified as a partial mediator of this relationship. Patients recognise the detrimental effects of disrupted sleep and are keen for treatment. All psychological intervention studies reported large effect size improvements in sleep and there may be modest resultant improvements in psychotic experiences.

CONCLUSIONS

Sleep disruption is a treatable clinical problem in patients with psychosis. It is important to treat in its own right but may also lessen psychotic experiences. Research is required on how this knowledge can be implemented in clinical services.

Controlled sleep deprivation as an experimental medicine model of schizophrenia: An update

In recent years there has been a surge of interest and corresponding accumulation of knowledge about the role of sleep disturbance in schizophrenia. In this review, we provide an update on the current status of experimentally controlled sleep deprivation (SD) as an experimental medicine model of psychosis, and also consider, given the complexity and heterogeneity of schizophrenia, whether this (state) model can be usefully combined with other state or trait model systems to more powerfully model the pathophysiology of psychosis. We present evidence of dose-dependent aberrations that qualitatively resemble positive, negative and cognitive symptoms of schizophrenia as well as deficits in a range of translational biomarkers for schizophrenia, including prepulse inhibition, smooth pursuit and antisaccades, following experimentally controlled SD, relative to standard sleep, in healthy volunteers. Studies examining the combination of SD and schizotypy, a trait model of schizophrenia, revealed only occasional, task-dependent superiority of the combination model, relative to either of the two models alone. Overall, we argue that experimentally controlled SD is a valuable experimental medicine model of schizophrenia to advance our understanding of the pathophysiology of the clinical disorder and discovery of more effective or novel treatments. Future studies are needed to test its utility in combination with other, especially state, model systems of psychosis such as ketamine.