The Prevalence of Sleep Disturbance and Its Socio-demographic and Clinical Correlates in First-episode Individuals With Schizophrenia in Rural China

The relationship between sleep and suicidality in schizophrenia spectrum and other psychotic disorders: A systematic review

Individuals with Schizophrenia Spectrum Disorders (SSDs) have significantly higher rates of suicidal thoughts, attempts, and death by suicide in comparison to the general population. Sleep disturbances (reduced duration, timing and quality of sleep) are risk factors for suicidality in the general population, with research indicating the relationship is both immediate and accumulative. Sleep disturbances are also considered to be implicated in the onset and exacerbation of psychotic symptoms in SSDs. Reducing the risk of suicidality in SSDs remains an important public health priority, thus exploration of contributing risk factors is warranted. Sleep monitoring may also offer an adjunct risk monitoring method to suicidality assessments in SSDs, and a potential treatment target for psychotic symptoms. This review aimed to explore proximal and longitudinal relationships between self-reported and objectively measured sleep and suicidality in SSDs and other psychotic disorders. A comprehensive search of four databases was conducted. Eleven studies met the inclusion criteria (10 cross sectional and 1 longitudinal). Narrative synthesis indicated that self-reported sleep disturbances and sleep disorders (e.g. insomnia) were associated with increased risk of suicidal ideation and attempt. However, one study employing polysomnography did not find sleep to be associated with suicidality. Methodological limitations of the evidence base include: i) little experimental or longitudinal evidence, (ii) self-report and/or single item assessment of sleep disturbance, (iii) limited use of validated measures of suicidality, (iv) considerable research in long-term schizophrenia but sparse evidence in early psychosis. Future research should explore (i) cross-sectional and longitudinal relationships between specific aspects of suicidality and objective sleep parameters, (ii) use qualitative or mixed-methods designs to disentangle the nuances and bidirectionality in the sleep-suicide relationship, (iii) explore the psychological processes underpinning or mediating the sleep-suicide relationship in SSDs.

Insomnia in Chinese patients with chronic schizophrenia: prevalence, clinical correlates and relationship with cognitive impairment

PURPOSE

Insomnia is a major public health concern that often occurs in patients with schizophrenia, complicating the treatment and prognosis of patients. This study aimed to investigate the prevalence of insomnia and its relationship with cognitive function in Chinese patients with chronic schizophrenia.

METHODS

We recruited patients with schizophrenia and collected their clinical and demographic data. Insomnia data were collected through a self-reported questionnaire consisting of three questions. The positive and negative syndrome scale (PANSS) was used to measure psychopathological symptoms, while the repeatable battery for the assessment of neuropsychological status (RBANS) was used to measure cognitive performance.

RESULTS

Of 957 Chinese patients with chronic schizophrenia 20.2% reported having insomnia (193/957). Male patients (107/630, 17.0%) had a lower rate of insomnia than female patients (86/327, 26.3%) (x2 = 11.60, p = 0.001). Patients with insomnia exhibited significantly higher PANSS total score and positive symptom, negative symptom, and general psychopathology scores, but significantly lower RBANS total score, language, attention and delayed memory scores compared to patients without insomnia (all p < 0.05). Logistic regression analysis showed that female sex, high PANSS total score and the use of diazepam were independently associated with insomnia (all p < 0.05).

CONCLUSIONS

Insomnia is relatively common in Chinese patients with chronic schizophrenia. Some demographic data and clinical symptoms are associated with insomnia. Patients with schizophrenia and insomnia perform poorly on cognition tests suggesting that insomnia and cognitive function are closely related in patients with schizophrenia.

A qualitative of stable symptomatology for patients with schizophrenia: do they have adequate post-discharge rehabilitative resources?

Many patients diagnosed with schizophrenia face obstacles to rehabilitation and discharge into the community, particularly with regard to the way resources are structured. Clarifying the difficulties will help health care providers address rehabilitation shortcomings. Semistructured in-depth interviews and participatory observations were conducted in various locations (family home, hospital ward, outpatient clinic, and on the street) with families, social workers, doctors, nursing staff, and patients with schizophrenia. These patients met the medical facility's hospital discharge standards and either had not been discharged or had been discharged within two weeks of meeting the discharge criteria. This study explores the complex and interdependent role of social differences in the rehabilitation of patients with schizophrenia after acute treatment. The study identified five topics related to structural difficulties in resources for the rehabilitation of patients diagnosed with schizophrenia: (1) the role of policy; (2) inadequate facilities and responsibilities; (3) rejecting communities; (4) difficult families; and (5) the threat of stigma. The rehabilitation of patients diagnosed with schizophrenia is a systemic problem. Systemic rehabilitation policies and integrated social support would be more conducive to the rehabilitation of patients. Perhaps cognitive remediation therapy or the Assertive Community Treatment (ACT) Model could benefit individuals with complex disorders.

Sex differences in prevalence and clinical correlates of insomnia in Chinese patients with chronic schizophrenia

OBJECTIVE

It is generally recognized that there are sex differences in many aspects of schizophrenia. The main purpose of this study was to investigate the sex differences in the prevalence and clinical correlates of insomnia in patients with chronic schizophrenia.

METHODS

A total of 957 patients who met the DSM-IV diagnostic criteria for schizophrenia were recruited in this cross-sectional study (male/female = 630/327). Demographic, clinical, and insomnia data were collected using self-reported questionnaires. Fasting blood samples were collected to evaluate the status of blood lipids. Psychopathological symptoms were evaluated using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

The prevalence rate of insomnia in female patients with schizophrenia was significantly higher than that in male patients (17.3% for males and 26.3% for females; χ² = 10.74, p = 0.001). Regression analysis showed that in male patients, insomnia was independently associated with severe PANSS positive symptoms, severe PANSS depressive factor, and high levels of low-density lipoprotein levels, while in female patients, insomnia was associated with low education level, high PANSS depressive factor, and high levels of apolipoprotein B levels.

CONCLUSION

This study illustrates that insomnia is more frequent in female than male schizophrenia patients, and that there are differences in the clinical correlates of insomnia by sex, suggesting that sex differences should be considered in prevention and treatment strategies for coexisting insomnia in schizophrenia patients.

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.

Sex difference in association between insomnia and cognitive impairment in patients with chronic schizophrenia

OBJECTIVE

Sex differences in schizophrenia have been noted across domains such as sleep and cognitive function； however, how they interact remains unclear. This study aimed to explore sex differences in the relationship between insomnia and cognitive function in patients with chronic schizophrenia.

METHODS

718 schizophrenia patients (480 males and 238 females) and 397 healthy controls were recruited. Insomnia was collected by a questionnaire. Insomnia severity index (ISI) was used to evaluate the severity of insomnia. The clinical symptoms and cognition were assessed with the Positive and Negative Syndrome Scale (PANSS) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), respectively.

RESULTS

Schizophrenia patients showed significantly lower scores compared to healthy controls on the RBANS total score and four indexes (all p < 0.05). Male patients had a lower rate of insomnia, higher scores on the RBANS visuospatial/constructional, language, and total score than female patients (all P < 0.05). Insomnia patients had lower RBANS immediate memory, language, and total scores than non-insomnia patients, and the results only appeared in female patients (all P < 0.05). In addition, there were significant negative correlations between ISI and RBANS language and delayed memory in male patients, while ISI was significantly negatively correlated with RBANS immediate memory in female patients (all P < 0.05).

CONCLUSION

Our findings suggest that there are sex differences in insomnia, cognitive performance, and their association in patients with chronic schizophrenia. These sex differences may have important potential clinical significance for the identification, evaluation, and treatment of insomnia in patients with chronic schizophrenia.

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.

The association between chronotype and sleep quality, and cardiometabolic markers in patients with schizophrenia

Current data on chronotype and sleep quality and their relationship with clinical characteristics of schizophrenia are insufficient to evaluate whether these variables are associated with cardiometabolic risk. We aimed to identify the interplay between chronotype, sleep quality and metabolic indices that can potentially predict negative cardiometabolic outcomes in schizophrenia patients. One-hundred schizophrenia patients who were under a stable antipsychotic regime were enrolled in the study. Clinical information, anthropometric measurements, as well as recent metabolic parameters including serum lipids, atherogenic, and metabolic indices suggestive of cardiometabolic risk were recorded. High and low sleep quality groups (HSQ and LSQ) were determined via the Pittsburgh Sleep Quality Index and chronotypes were evaluated with the Morningness-Eveningness Questionaire. Patients with eveningness chronotype had poorer sleep quality compared to intermediate or morningness (p = .017) patients. The LSQ group had higher total cholesterol (p = .004) and low-density lipoprotein (LDL) (p = .041) compared to the HSQ group. Mean blood pressure was higher in the eveningness chronotype patients compared to intermediate or morningness patients (p = .015). According to a logistic regression model, total cholesterol, disposition index, and having an eveningness chronotype significantly predicted LSQ in schizophrenia. Eveningness chronotype may lead to impaired cardiometabolic regulation with the mediation of poor sleep quality in schizophrenia patients. Cardiovascular diseases, sleep quality, and sleep patterns can influence each other; thus, this complex relationship in schizophrenia should be considered while configuring both pharmacological and behavioral interventions.

"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.

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.

Comorbidity rates of depression and anxiety in first episode psychosis: A systematic review and meta-analysis

Anxiety and depression symptoms are frequently experienced by individuals with psychosis, although prevalence rates have not been reviewed in first-episode psychosis (FEP). The aim of this systematic review was to focus on the prevalence rates for both anxiety and depression, comparing the rates within the same study population. A systematic review and meta-analysis was completed for all studies measuring both anxiety and depression in FEP at baseline. The search identified 6040 citations, of which n = 10 met inclusion criteria. These reported 1265 patients (age 28.3 ± 9.1, females: 39.9%) with diagnosed FEP. Studies which used diagnosis to define comorbidity count were included in separate meta-analyses for anxiety and depression, although the heterogeneity was high limiting interpretation of separate prevalence rates. A random-effects meta-analysis also compared the mean difference between anxiety and depression within the same studies. We show that anxiety and depression co-occur at a similar rate within FEP, although the exact rates are not reliable due to the heterogeneity between the small number of studies. Future research in FEP should consider routinely measuring anxiety and depression using continuous self-report measures of symptoms. Clinically we recommend that both anxiety and depression are equally targeted during psychological intervention in FEP, together with the psychotic symptoms.

Basic Neuroscience Illuminates Causal Relationship Between Sleep and Memory: Translating to Schizophrenia

Patients with schizophrenia are often plagued by sleep disturbances that can exacerbate the illness, including potentiating psychosis and cognitive impairments. Cognitive dysfunction is a core feature of schizophrenia with learning and memory being particularly impaired. Sleep disruptions often accompanying the illness and may be key mechanism that contribute to these core dysfunctions. In this special translational neuroscience feature, we highlight the role of sleep in mediating cognitive function, with a special focus on learning and memory. By defining dysfunctional sleep architecture and rhythms in schizophrenia, we focus on the disarray of mechanisms critical to learning and memory and postulate an association between sleep disturbances and cognitive impairments in the disorder. Lastly, we review preclinical models of schizophrenia and highlight exciting translational research that may lead to new therapeutic approaches to alleviating sleep disturbances and effectively improving cognitive function in schizophrenia.