Sleep in first-episode schizophrenia patients, their unaffected siblings and healthy controls: A comparison

BACKGROUND

Sleep disturbances in schizophrenia are common throughout its course including in the prodrome, and have been mainly attributed to severity of symptoms and antipsychotic use. We aimed to investigate whether early course patients with schizophrenia and young non-psychotic siblings of patients with schizophrenia also show sleep disturbances and whether sleep correlates with symptoms and functioning.

METHODS

Three study groups, that is, adults newly diagnosed with schizophrenia (n = 54), young non-psychotic siblings of schizophrenia patients (n = 56) and a sample of healthy controls matched to the patients and siblings (n = 61) were evaluated on Horne and Ostberg Morningness-Eveningness Questionnaire, Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index. Severity of symptoms and functioning are assessed using the Positive and Negative Syndrome Scale and the Global Assessment of Functioning Scale, respectively. Age, gender, occupation and marital status were regarded as covariates, and differences between the three groups were evaluated using analysis of covariance.

RESULTS

Early course schizophrenia patients and non-psychotic siblings of schizophrenia patients showed significantly reduced sleep quality relative to healthy controls (P < .001). Schizophrenia patients had significantly higher daytime sleepiness compared to controls (P < .001). Chronotypes in schizophrenia patients and unaffected siblings did not significantly differ from those of the healthy controls.

CONCLUSIONS

Like chronic medicated schizophrenia patients, early course schizophrenia patients and young non-psychotic siblings of individuals with schizophrenia have sleep disturbances. These findings indicate that sleep markers can distinguish unaffected siblings of schizophrenia from healthy controls and serve as an endophenotype for schizophrenia.

The Drosophila ortholog of the schizophrenia-associated CACNA1A and CACNA1B voltage-gated calcium channels regulate memory, sleep and circadian rhythms

Schizophrenia exhibits up to 80% heritability. A number of genome wide association studies (GWAS) have repeatedly shown common variants in voltage-gated calcium (Ca_v) channel genes CACNA1C, CACNA1I and CACNA1G have a major contribution to the risk of the disease. More recently, studies using whole exome sequencing have also found that CACNA1B (Ca_v2.2 N-type) deletions and rare disruptive variants in CACNA1A (Ca_v2.1 P/Q-type) are associated with schizophrenia. The negative symptoms of schizophrenia include behavioural defects such as impaired memory, sleep and circadian rhythms. It is not known how variants in schizophrenia-associated genes contribute to cognitive and behavioural symptoms, thus hampering the development of treatment for schizophrenia symptoms. In order to address this knowledge gap, we studied behavioural phenotypes in a number of loss of function mutants for the Drosophila ortholog of the Ca_v2 gene family called cacophony (cac). cac mutants showed several behavioural features including decreased night-time sleep and hyperactivity similar to those reported in human patients. The change in timing of sleep-wake cycles suggested disrupted circadian rhythms, with the loss of night-time sleep being caused by loss of cac just in the circadian clock neurons. These animals also showed a reduction in rhythmic circadian behaviour a phenotype that also could be mapped to the central clock. Furthermore, reduction of cac just in the clock resulted in a lengthening of the 24 h period. In order to understand how loss of Ca_v2 function may lead to cognitive deficits and underlying cellular pathophysiology we targeted loss of function of cac to the memory centre of the fly, called the mushroom bodies (MB). This manipulation was sufficient to cause reduction in both short- and intermediate-term associative memory. Memory impairment was accompanied by a decrease in Ca²⁺ transients in response to a depolarizing stimulus, imaged in the MB presynaptic terminals. This work shows loss of cac Ca_v2 channel function alone causes a number of cognitive and behavioural deficits and underlying reduced neuronal Ca²⁺ transients, establishing Drosophila as a high-throughput in vivo genetic model to study the Ca_v channel pathophysiology related to schizophrenia.

Sleep, sleep spindles, and cognitive functions in drug-naive patients with first-episode psychosis

STUDY OBJECTIVES

Various lines of clinical findings have suggested abnormalities in macro- or microstructural parameters of sleep in patients with schizophrenia. Meanwhile findings are inconclusive due to some confounding factors, such as the heterogeneity of the disorder, drug regimen, and duration of the illness. There are a few studies in the literature that have been conducted on drug-free patients with first-episode psychosis (FEP). Based on this knowledge, we aimed to explore sleep characteristics, sleep spindles, and neuropsychological profiles of the drug-naive patients with FEP.

METHODS

The study sample consisted of 21 drug-naive patients with FEP and 21 healthy participants. Polysomnography recordings were conducted for 2 subsequent nights. A neuropsychological test battery was administered for assessing cognitive functions. The Positive and Negative Syndrome Scale was applied to measure symptom severity of the patients. Spindle detection was performed visually.

RESULTS

According to the results of the study, the patient group's percentage of stage N2 sleep and sleep efficiency index was lower than in the control group. Among sleep spindle parameters, spindle density was found to be reduced in the patient group. The results of neuropsychological tests measuring executive functions, learning, and memory support the idea that there is a global cognitive deterioration from the early course of the disorder. In the psychotic group, negative symptoms were negatively correlated with verbal memory, learning, verbal fluency, and semantic organization. We found that the percentage of stage N3 sleep decreased while negative symptom severity increased. In addition, the percentage of stage N1 sleep increased as negative symptom severity increased. Reduction in stage N3 sleep was associated with an impairment in learning, verbal fluency, and response inhibition. The sleep spindle density and cognitive functions did not show any associations.

CONCLUSIONS

Taken together, these findings suggest that patients with FEP show global cognitive impairment (except for attention and processing speed), which is associated with changes in sleep architecture and higher score in a scale assessing negative symptoms. We conclude that cognitive function and spindle parameters differ nonlinearly among patients with FEP.

Troubles psychotiques et troubles du sommeil : revue de la littérature

Contexte La disparition de la nomenclature des troubles du sommeil dits primaires ou secondaires, rendue obsolète par le Manuel diagnostique et statistique des troubles mentaux (DSM-5), représente bien l’engouement académique actuel pour ce domaine de recherche. Il est de plus en plus reconnu que les troubles du sommeil sont plus que de simples conséquences d’un trouble psychiatrique et qu’ils peuvent persister malgré un traitement adéquat de la condition comorbide et même précéder ou exacerber cette dernière. Les troubles du sommeil dans les troubles psychotiques, très fréquents, sont donc devenus un sujet d’actualité, représentant une cible d’intervention jusqu’ici sous-estimée.

Objectif Cet article vise à présenter l’état des connaissances actuelles sur la relation entre les troubles du sommeil et les troubles psychotiques ainsi que sur l’utilisation de la thérapie cognitivo-comportementale (TCC) pour traiter les troubles du sommeil dans ce contexte.

Méthode L’article fait une recension narrative de la littérature pour décrire la relation bidirectionnelle entre la psychose et les troubles du sommeil, les corrélations cliniques et les traitements ciblant l’insomnie chez les patients psychotiques.

Résultats Malgré la présence d’une relation entre les troubles du sommeil et les troubles psychotiques, les mécanismes neuronaux, hormonaux et socioculturels régissant cette relation demeurent encore incertains. Bien que l’association reliant les troubles du sommeil et les troubles psychotiques demeure à clarifier, les études démontrent qu’elle serait bidirectionnelle et peut engendrer un cercle vicieux où ces deux composantes s’aggravent mutuellement. Dans ce contexte de comorbidités, les modèles unifiés en TCC deviennent un traitement de choix, à condition d’adapter les protocoles de TCC pour insomnie (TCC-i) à une population avec trouble psychotique (TCC-ip).

Conclusion Malgré la complexité de la relation entre les troubles psychotiques et ceux du sommeil, la TCC-i a été démontrée efficace pour traiter les troubles du sommeil dans une population psychotique et pourrait, dans certains cas, permettre d’alléger la symptomatologie psychotique. De futures études sur ce domaine pourraient permettre le développement de protocoles de thérapie cognitivo-comportementale pour les troubles du sommeil mieux adaptés à la population avec troubles psychotiques.

Self-Reported Sleep and Exercise Patterns in Patients with Schizophrenia: a Cross-Sectional Comparative Study

BACKGROUND

Adequate sleep and physical activity have been linked to the overall well-being of both medical and psychiatric patients. Patients with schizophrenia have shown abnormal sleep patterns and decreased physical activity that were linked to their psychopathology and physical health. These phenomena are not studied yet in Arab patients with schizophrenia. The purpose of this study is to study the sleep and exercise patterns in Arab patients with schizophrenia compared with those of healthy controls.

METHOD

A total of 99 patients with schizophrenia and 101 controls were recruited. Arabic versions of sleep, exercise, socio-demographic, and clinical questionnaires were administered as well as the validated scales to measure psychopathology, depression, and suicidality in these participants.

RESULTS

The majority of patients with schizophrenia slept more than 8 h per day and exercised less when compared with controls. Sleep quality was worse in those with higher depression score and higher suicidality scores were seen in patients with lower sleep duration. Multinomial regression showed that patients with schizophrenia have higher odds of sleeping more than 8 h even after controlling for the intake of antipsychotics, age, gender, smoking status, and other confounding factors.

CONCLUSION

Our results showed that Arab patients with schizophrenia are at increased risk of having longer sleep duration with inadequate physical activity, which are correlating with worsening of depressive symptoms and suicidality. Thus, more attention should be paid to the changes in sleep patterns and level of exercise when treating Arab patients with schizophrenia.

Physical health assistance in early recovery of psychosis: Study protocol for a randomized controlled trial

AIM

Young people with psychotic disorders have poorer physical health compared to their healthy peers, a state compounded by the metabolic side-effects of antipsychotic medications. To address this, Orygen Youth Health has introduced physical health services including exercise physiologists and dieticians. These services are typically coordinated by the case manager and doctor. It is not yet known whether a treating team member dedicated to physical health will improve engagement, adherence and outcomes with these services. Hence, the protocol is presented here for a trial to evaluate the effect of including a physical health nurse in the care of young people with first-episode psychosis.

METHODS

This will be a single-blind randomized controlled trial that includes 15- to 24-year-olds with first-episode psychosis who have just commenced (within 30 days) antipsychotic medication. The primary outcome will be the event of clinically significant weight gain (≥7% body weight). Participants will be assigned either a physical health nurse in their treating team (in addition to the case manager and doctor) for a 12-week period, or treatment as usual (case manager and doctor). Research assessments will be conducted at baseline, 12 and 26 weeks. Activity trackers worn by participants for the study's duration will measure sleep and physical activity.

CONCLUSION

The present study will determine whether a physical health nurse will facilitate participants in attending and engaging in physical health interventions and whether this will be associated with physical health improvements or the prevention of worsening physical health.

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

Experimental research has shown that poor sleep triggers psychotic experiences, even in healthy participants. This warrants an in-depth investigation of this mechanism in a naturalistic environment, an exploration of which particular aspects of poor sleep trigger psychotic symptoms, and a test for reverse effects of symptoms on sleep. For this purpose, we conducted a 14-day ambulatory assessment study with 82 young adults (age: M = 21.24 years, SD = 1.54; 64.6% female), half of which were characterized by elevated psychosis proneness. Objective sleep parameters (actigraphically-measured sleep time, wake after sleep onset, sleep efficiency), self-reported sleep parameters (feeling rested, dream recall, dream valence), and psychotic symptoms (paranoid symptoms, hallucinatory experiences) were assessed once per day. Using multilevel regressions (928 data points), we found that shorter sleep time and negative dream valence predicted paranoid symptoms, whereas feeling less rested and dream recall predicted hallucinatory experiences. In participants with elevated psychosis proneness, associations with the aforementioned sleep parameters were increased for hallucinatory experiences but not for paranoid symptoms. Finally, we found bidirectional associations between poor sleep and paranoid symptoms but only unidirectional associations between poor sleep and hallucinatory experiences. The findings corroborate the relevance of sleep disturbance as a predictor of psychotic experiences. Future studies should further investigate the potential of sleep interventions to prevent psychotic symptoms and disorders.

Sex Differences in Subjective Sleep Quality Patterns in Schizophrenia

OBJECTIVE/BACKGROUND

Sleep dysfunction is prevalent among patients with schizophrenia. Although sex differences have been identified in schizophrenia, sex differences in sleep patterns among patients with schizophrenia are not established. Therefore, the current study examined sex differences in subjective sleep quality patterns in people with schizophrenia utilizing a standardized inventory.

PARTICIPANTS

Study sample consisted of 75 patients with schizophrenia and 82 healthy controls (HC).

METHODS

Participants completed the Pittsburgh Sleep Quality Index (PSQI).

RESULTS

Compared to HC, patients with schizophrenia were more likely to report being poor sleepers (PSQI global score > 5), longer sleep duration, more sleep disturbances, longer sleep onset latency, increased daytime dysfunction due to poor sleep, and more frequent use of sleep medications. Regarding sex differences, female patients were more likely to report being poor sleepers and endorsed more sleep disturbances than female HC, while male patients reported longer sleep duration, more daytime dysfunction, and poorer overall sleep quality relative to male HC. Additionally, higher level of sleep dysfunction was linked to higher symptom severity in male patients only.

CONCLUSIONS

Patients with schizophrenia endorsed a range of sleep difficulties, and male and female patients with schizophrenia differ compared to their HC counterparts. Implications for treatment of sleep complaints among patients with schizophrenia are discussed.

Sleep, circadian rhythms, and schizophrenia: where we are and where we need to go

PURPOSE OF REVIEW

The review is designed to give an overview of the latest developments in research exploring the relationship between sleep and psychosis, with particular attention paid to the evidence for a causal relationship between the two.

RECENT FINDINGS

The most interesting avenues currently in pursuit are focused upon sleep spindle deficits which may hallmark an endophenotype; explorations of the continuum of psychotic experiences, and experimental manipulations to explore the evidence for bidirectional causality; inflammatory markers, psychosis and sleep disturbances and finally, treatment approaches for sleep in psychosis and the subsequent impact on positive experiences.

SUMMARY

Globally, large surveys and tightly controlled sleep deprivation or manipulation experiments provide good evidence for a cause-and-effect relationship between sleep and subclinical psychotic experiences. The evidence for cause-and-effect using a interventionist-causal model is more ambiguous; it would appear treating insomnia improves psychotic experiences in an insomnia cohort but not in a cohort with schizophrenia. This advocates the necessity for mechanism-driven research with dimensional approaches and in depth phenotyping of circadian clock-driven processes and sleep regulating functions. Such an approach would lead to greater insight into the dynamics of sleep changes in healthy and acute psychosis brain states.

The interaction between subclinical psychotic experiences, insomnia and objective measures of sleep

Investigations into schizophrenia have revealed a high incidence of comorbidity with disturbed sleep and circadian timing. Acknowledging this comorbidity on a dimensional level, we tested prospectively whether subclinical psychotic symptoms are more prevalent in individuals with insomnia. An insomnia group (n=21) and controls (n=22) were recruited on their subjective sleep quality, recorded actigraphically for 3weeks and assessed for psychotic-like experiences with The Prodromal Questionnaire-16. Using multivariate Poisson regression analyses, we found that objective and subjective sleep measures interact to predict the highest risk for psychotic experiences. Objective measures of sleep and statistical modelling are rarely used in either clinical trials or practice for schizophrenia, yet this study highlights their value in these areas.

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

Paranoid symptoms co-occur with distress and poor functioning and constitute a risk for psychosis and other mental disorders. Poor sleep is known to be associated with paranoid symptoms, but the direction of the effect and the mediating factors have not been studied thoroughly. In an experience-sampling study, 61 adolescents wore an actigraph over eight nights and also rated their sleep, symptoms of paranoia, and potentially mediating factors. Shorter sleep time and more dreaming predicted paranoid symptoms in multilevel regression models. Paranoid symptoms did not significantly predict sleep parameters. Positive and negative affect partially mediated the effect of sleep time on paranoid symptoms. The effects were small, but encourage further research that might then be used to improve the prevention of paranoid symptoms.

Sleep Disturbances in Schizophrenia

Sleep disturbances are prevalent in patients with schizophrenia and play a critical role in the morbidity and mortality associated with the illness. Subjective and objective assessments of sleep in patients with schizophrenia have identified certain consistent findings. Findings related to the sleep structure abnormalities have shown correlations with important clinical aspects of the illness. Disruption of specific neurotransmitter systems and dysregulation of clock genes may play a role in the pathophysiology of schizophrenia-related sleep disturbances. Antipsychotic medications play an important role in the treatment of sleep disturbances in these patients and have an impact on their sleep structure.

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

BACKGROUND

Sleep dysfunction is extremely common in patients with schizophrenia. Recent research indicates that sleep dysfunction may contribute to psychotic experiences such as delusions and hallucinations.

OBJECTIVES

The review aims to evaluate the evidence for a relationship between sleep dysfunction and individual psychotic experiences, make links between the theoretical understanding of each, and highlight areas for future research.

METHOD

A systematic search was conducted to identify studies investigating sleep and psychotic experiences across clinical and non-clinical populations.

RESULTS

66 papers were identified. This literature robustly supports the co-occurrence of sleep dysfunction and psychotic experiences, particularly insomnia with paranoia. Sleep dysfunction predicting subsequent psychotic experiences receives support from epidemiological surveys, research on the transition to psychosis, and relapse studies. There is also evidence that reducing sleep elicits psychotic experiences in non-clinical individuals, and that improving sleep in individuals with psychosis may lessen psychotic experiences. Anxiety and depression consistently arise as (partial) mediators of the sleep and psychosis relationship.

CONCLUSION

Studies are needed that: determine the types of sleep dysfunction linked to individual psychotic experiences; establish a causal connection between sleep and psychotic experiences; and assess treatments for sleep dysfunction in patients with non-affective psychotic disorders such as schizophrenia.

Sleep-dependent memory consolidation and its implications for psychiatry

Both sleep disturbance and memory impairment are very common in psychiatric disorders. Since sleep has been shown to play a role in the process of transferring newly acquired information into long-term memory, i.e., consolidation, it is important to highlight this link in the context of psychiatric disorders. Along these lines, after providing a brief overview of healthy human sleep, current neurobiological models on sleep-dependent memory consolidation and resultant opportunities to manipulate the memory consolidation process, recent findings on sleep disturbances and sleep-dependent memory consolidation in patients with insomnia, major depression, schizophrenia, and post-traumatic stress disorder are systematically reviewed. Furthermore, possible underlying neuropathologies and their implications on therapeutic strategies are discussed. This review aims at sensitizing the reader for recognizing sleep disturbances as a potential contributor to cognitive deficits in several disorders, a fact which is often overlooked up to date.

Actigraphic-measured sleep disturbance predicts increased positive symptoms in adolescents at ultra high-risk for psychosis: A longitudinal study

BACKGROUND

Sleep disturbance is prevalent among patients with psychosis, yet little is known about sleep health during the ultra high-risk (UHR) period. This study used actigraphy to evaluate sleep in healthy control (HC) and UHR adolescents to examine the relationship between sleep disturbance and psychosis symptoms at baseline and 12-month follow-up, as well as comparisons between objective and subjective measurements of sleep functioning in UHR youth.

METHOD

Thirty-six UHR and 31 HC youth participated in a baseline evaluation including 5 nights of actigraphy, subjective measurement of sleep health (Pittsburgh Sleep Quality Index; PSQI), and clinical interviews. Clinical measures were repeated with UHR youth (N=23) at a 12-month follow-up.

RESULTS

The actigraphy data indicated that UHR youth displayed increased wake time after onset (WASO), increased movements during sleep, and decreased efficiency compared to HC, and several markers of sleep disturbance including decreased efficiency, increased WASO, number of awakenings, and increased movements were associated with symptomatology in the UHR group. Interestingly, there were associations between actigraph and self-report indices of sleep duration and efficiency (at the trend level) but not awakenings. Several objective measures of sleep disturbance and one self-reported measure (disrupted continuity) predicted the longitudinal course of symptoms over 12 months in the UHR group.

CONCLUSIONS

Taken together, the results suggest a potential role for sleep problems in the etiology of schizophrenia, and highlight sleep health as a possible target for prevention/intervention efforts. Additionally, actigraphy represents an inexpensive, sensitive measurement providing unique information not captured by self-report, and may be an informative adjunct to UHR assessments.

Diagnosis and treatment of sleep apnoea in women with schizophrenia

BACKGROUND

Obstructive sleep apnoea (OSA) is often overlooked in the context of schizophrenia because its hallmark, daytime sleepiness, is so easily attributable to antipsychotic drugs. This is a special problem for women.

AIMS

To underscore the importance of diagnosing and treating OSA in women with schizophrenia.

METHODS

A review of the recent literature (search terms: Obstructive Sleep Apnoea; Schizophrenia; Women (or Gender); Obesity; Antipsychotics; Continuous Positive Airway Pressure (CPAP)) as it applies to a composite case vignette taken from the files of a specialty clinic that treats women with psychosis.

RESULTS

The rate of OSA in women who are both obese and postmenopausal is very similar to that of men. Family history, smoking, and the use of tobacco, alcohol and of antipsychotic medication increase the risk. Despite reluctance, patients with schizophrenia generally agree to undergo sleep studies. Compliance with CPAP is difficult, but can be aided by the physician and is, on the whole, relatively high in women. CPAP improves sleep parameters and may also improve cardiometabolic and cognitive indices, although this still needs to be more fully researched.

CONCLUSION

Schizophrenia and untreated OSA are both associated with high mortality rates in women as well as men.

Sleep dysfunction and thalamic abnormalities in adolescents at ultra high-risk for psychosis

BACKGROUND

Sleep dysfunction is a pervasive, distressing characteristic of psychosis, yet little is known regarding sleep quality prior to illness onset. At present, it is unclear whether sleep dysfunction precedes the emergence of psychotic symptoms, signifying a core feature of the disorder, or if it represents a consequence of prolonged contact with aspects of schizophrenia and its treatment (e.g., medication use or neurotoxicity) or co-morbid symptoms (e.g., depressive and manic symptomatology). The current study examined sleep dysfunction in adolescents at ultra high-risk (UHR) for psychosis, relationships between sleep disturbances and psychosis symptoms, volume of an integral sleep-structure (thalamus), and associations between thalamic abnormalities and sleep impairment in UHR youth.

METHOD

Thirty-three UHR youth and 33 healthy controls (HC) participated in a self-assessment of sleep functioning (Pittsburgh Sleep Quality Index; PSQI), self and parent-report clinical interviews, and structural magnetic resonance imaging (MRI).

RESULTS

UHR adolescents displayed increased latency to sleep onset and greater sleep disturbances/disrupted continuity compared to HC youth, over and above concurrent mood symptoms. Among UHR youth, increased sleep dysfunction was associated with greater negative symptom severity but not positive symptoms. Compared to HC adolescents, UHR participants displayed decreased bilateral thalamus volume, which was associated with increased sleep dysfunction.

CONCLUSIONS

Sleep dysfunction occurs during the pre-psychotic period, and may play a role in the etiology and pathophysiology of psychosis. In addition, the relationship of disrupted sleep to psychosis symptoms in UHR youth indicates that prevention and intervention strategies may be improved by targeting sleep stabilization in the pre-psychotic period.