Sleep in Schizophrenia: Pathology and Treatment

Antipsychotic medications and sleep problems in patients with schizophrenia

BACKGROUND

Sleep problems are common and related to a worse quality of life in patients with schizophrenia. Almost all patients with schizophrenia use antipsychotic medications, which usually increase sleep. Still, the differences in subjective sleep outcomes between different antipsychotic medications are not entirely clear.

METHODS

This study assessed 5466 patients with schizophrenia and is part of the nationwide Finnish SUPER study. We examined how the five most common antipsychotic medications (clozapine, olanzapine, quetiapine, aripiprazole, and risperidone) associate with questionnaire-based sleep problems in logistic regression analyses, including head-to-head analyses between different antipsychotic medications. The sleep problems were difficulties initiating sleep, early morning awakenings, fatigue, poor sleep quality, short (≤6 h) and long sleep duration (≥10 h).

RESULTS

The average number of antipsychotic medications was 1.59 per patient. Clozapine was associated with long sleep duration (49.0 % of clozapine users vs 30.2 % of other patients, OR = 2.05, 95 % CI 1.83-2.30, p < .001). Olanzapine and risperidone were in head-to-head analyses associated with less sleep problems than patients using aripiprazole, quetiapine, or no antipsychotic medication. Aripiprazole and quetiapine were associated with more insomnia symptoms and poorer sleep quality. Patients without antipsychotic medications (N = 159) had poorer sleep quality than patients with antipsychotic use, and short sleep duration was common (21.5 % of patients not using antipsychotics vs 7.8 % of patients using antipsychotics, OR = 2.97, 95 % CI 1.98-4.44, p < .001).

CONCLUSIONS

Prevalence of sleep problems is markedly related to the antipsychotic medication the patient uses. These findings underline the importance of considering and assessing sleep problems when treating schizophrenia patients with antipsychotics.

The associations between daily reports of loneliness and psychotic experiences in the early risk stages for psychosis

AIM

Bi-directional associations between loneliness and psychotic experiences (PEs) have been reported, but the mechanisms underlying these associations are unknown. This study aims to explore associations between daily reports of loneliness and PEs, and test differences in this association across young adult individuals at different levels of risk for psychosis.

METHODS

We analysed 90-day diary data on loneliness and PEs from N = 96 participants (mean age 24.7, range 18-35, 77% female) divided into 4 subgroups, each indexing increased levels of risk for psychosis according to the clinical staging model: 'psychometric' (n = 25), 'low' (n = 27), 'mild' (n = 24), and 'ultra-high'(n = 20) risk. Multilevel vector autoregressive models examined within-day (contemporaneous) and between-day (temporal) associations between loneliness and PEs for the total sample. Next, these associations were compared across subgroups.

RESULTS

Loneliness and PEs were significantly associated contemporaneously (partial correlation B = 0.14) but not temporally. Subgroup membership moderated both contemporaneous and temporal associations. The contemporaneous association between loneliness and PEs was stronger in the low-risk subgroup compared to the mild-risk (B = -0.35, p < .01) and ultra-high-risk (B = -0.36, p < .01) subgroups. The temporal association between loneliness on the previous day and PEs on the current day was stronger in mild-risk subgroup compared to the ultra-high-risk subgroup (B = -0.03, p = .03). After adjusting for multiple testing, only the contemporaneous-but not the temporal-associations remained statistically significant.

CONCLUSIONS

Loneliness is associated with PEs in individuals at risk for psychosis, particularly in those with low to mild symptoms. Our findings tentatively suggest that especially individuals with low expressions of PEs may be more sensitive to social context, but future studies are needed to replicate and further unravel the potentially stage-specific interplay between social context and PEs.

Predicting new onset thought disorder in early adolescence with optimized deep learning implicates environmental-putamen interactions

Background

Thought disorder (TD) is a sensitive and specific marker of risk for schizophrenia onset. Specifying factors that predict TD onset in adolescence is important to early identification of youth at risk. However, there is a paucity of studies prospectively predicting TD onset in unstratified youth populations.

Study Design

We used deep learning optimized with artificial intelligence (AI) to analyze 5,777 multimodal features obtained at 9-10 years from youth and their parents in the ABCD study, including 5,014 neural metrics, to prospectively predict new onset TD cases at 11-12 years. The design was replicated for all prevailing TD cases at 11-12 years.

Study Results

Optimizing performance with AI, we were able to achieve 92% accuracy and F1 and 0.96 AUROC in prospectively predicting the onset of TD in early adolescence. Structural differences in the left putamen, sleep disturbances and the level of parental externalizing behaviors were specific predictors of new onset TD at 11-12 yrs, interacting with low youth prosociality, the total parental behavioral problems and parent-child conflict and whether the youth had already come to clinical attention. More important predictors showed greater inter-individual variability.

Conclusions

This study provides robust person-level, multivariable signatures of early adolescent TD which suggest that structural differences in the left putamen in late childhood are a candidate biomarker that interacts with psychosocial stressors to increase risk for TD onset. Our work also suggests that interventions to promote improved sleep and lessen parent-child psychosocial stressors are worthy of further exploration to modulate risk for TD onset.

Efficacy of music therapy and predictors of sleep disturbance among patients with chronic schizophrenia: A prospective study

STUDY OBJECTIVES

Patients with schizophrenia often suffer from sleep disturbance. Music therapy, as a non-invasive intervention, may have benefit on sleep problem in such population. Our study aimed to investigate the efficacy of music therapy on sleep disturbance among patients with schizophrenia.

METHOD

This prospective study recruited participants with schizophrenia along with sleep disturbances in the chronic wards. Patients in the control group received standard care, and those in the intervention group received additional music therapy before sleeping at night for four weeks. The Pittsburgh Sleep Quality Index (PSQI) was used to measure the severity of sleep disturbance. The generalized estimating equation (GEE) was used to analyze measure the difference of change in PSQI scores between both groups at the baseline and four weeks later. It was also applied to find the predictors of treatment efficacy within intervention group.

FINDINGS

A total of 66 (31 in control group and 35 in intervention group) participants were recruited. After adjusting with the demographic variables, the change of PSQI among intervention group was significantly more than the change among control group (Group × time; Estimate = -7.05, p < 0.001), indicating the efficacy of music therapy. In addition, irreligious patients and those with chronic medical disease predicted better efficacy. Whereas, elderly patients had compromising efficacy of music therapy.

CONCLUSION

Music therapy demonstrated its merit on sleep disturbance among patients with schizophrenia. Whereas, healthcare workers should consider the variability of severity in schizophrenia during clinical practice.

Antipsychotic polypharmacy and clozapine prescribing patterns: evolution and correlates before and after a psychiatric hospitalisation

BACKGROUND

Antipsychotic polypharmacy (APP) prescribing and clozapine underuse are considered inappropriate prescribing in schizophrenia. Psychiatric hospitalisations may be suitable occasions to re-evaluate patient pharmacotherapy and to switch to monotherapy.

OBJECTIVES

To explore the evolution of APP and other psychotropic prescribing patterns during psychiatric hospitalisations, to detect characteristics associated with APP on admission and at discharge, and to examine clozapine prescribing patterns.

DESIGN

We performed a retrospective observational study based on electronic health records.

METHODS

Data on adult inpatients diagnosed with schizophrenia spectrum disorders were collected retrospectively from 6 Belgian hospitals in 2020-2021.

RESULTS

Of the 516 patients included, APP prescribing increased significantly from 47.9% on hospital admission to 59.1% at discharge. On admission and at discharge, APP was associated with prior clozapine use (OR_admission = 2.53, CI = 1.1-5.84, OR_discharge = 11.01, CI = 4.45-27.28), treatment with a first-generation antipsychotic (OR_admission = 26.79, CI = 13.08-54.86, OR_discharge = 25.2, CI = 12.2-52.04), increased antipsychotic exposure (OR_admission = 8.93, CI = 5.13-15.56, OR_discharge = 19.89, CI = 10-39.54), and a greater number of hypno-sedatives (OR_admission = 1.88, CI = 1.23-2.88, OR_discharge = 4.18, CI = 2.53-6.91). APP was negatively associated with involuntary admission (OR_admission = 0.31, CI = 0.14-0.7, OR_discharge = 0.3, CI = 0.13-0.68). When using an alternative definition of monotherapy (i.e. including patients with an add-on low-dose antipsychotic for sleep disorders), alcohol use disorder (OR_admission = 0.26, CI = 0.13-0.54) and higher age (OR_discharge = 0.53, CI = 0.29-0.95) were negatively associated with APP, and living in a residential facility (OR_discharge = 2.39 CI = 1.21-4.71) and a higher daily dosage of benzodiazepines during the stay (OR_discharge = 1.32 CI = 1.03-1.69) increased the odds of being discharged on APP. On admission, 9.3% of patients were being treated with clozapine. Although 28.1% of patients were eligible for clozapine treatment, only 11% of patients were discharged with a clozapine prescription. For 7 of the 10 patients with a new clozapine prescription, it was directly prescribed in combination with another antipsychotic, without a prior trial of clozapine monotherapy.

CONCLUSION

Suboptimal prescriptions of antipsychotics in patients with schizophrenia persist after psychiatric hospitalisations and are associated with identifiable characteristics.

Covering the Gap Between Sleep and Cognition – Mechanisms and Clinical Examples

A growing number of studies have shown the strong relationship between sleep and different cognitive processes, especially those that involve memory consolidation. Traditionally, these processes were attributed to mechanisms related to the macroarchitecture of sleep, as sleep cycles or the duration of specific stages, such as the REM stage. More recently, the relationship between different cognitive traits and specific waves (sleep spindles or slow oscillations) has been studied. We here present the most important physiological processes induced by sleep, with particular focus on brain electrophysiology. In addition, recent and classical literature were reviewed to cover the gap between sleep and cognition, while illustrating this relationship by means of clinical examples. Finally, we propose that future studies may focus not only on analyzing specific waves, but also on the relationship between their characteristics as potential biomarkers for multiple diseases.

Alterations in TRN-anterodorsal thalamocortical circuits affect sleep architecture and homeostatic processes in oxidative stress vulnerable Gclm-/- mice

Schizophrenia is associated with alterations of sensory integration, cognitive processing and both sleep architecture and sleep oscillations in mouse models and human subjects, possibly through changes in thalamocortical dynamics. Oxidative stress (OxS) damage, including inflammation and the impairment of fast-spiking gamma-aminobutyric acid neurons have been hypothesized as a potential mechanism responsible for the onset and development of schizophrenia. Yet, the link between OxS and perturbation of thalamocortical dynamics and sleep remains unclear. Here, we sought to investigate the effects of OxS on sleep regulation by characterizing the dynamics of thalamocortical networks across sleep-wake states in a mouse model with a genetic deletion of the modifier subunit of glutamate-cysteine ligase (Gclm knockout, KO) using high-density electrophysiology in freely-moving mice. We found that Gcml KO mice exhibited a fragmented sleep architecture and impaired sleep homeostasis responses as revealed by the increased NREM sleep latencies, decreased slow-wave activities and spindle rate after sleep deprivation. These changes were associated with altered bursting activity and firing dynamics of neurons from the thalamic reticularis nucleus, anterior cingulate and anterodorsal thalamus. Administration of N-acetylcysteine (NAC), a clinically relevant antioxidant, rescued the sleep fragmentation and spindle rate through a renormalization of local neuronal dynamics in Gclm KO mice. Collectively, these findings provide novel evidence for a link between OxS and the deficits of frontal TC network dynamics as a possible mechanism underlying sleep abnormalities and impaired homeostatic responses observed in schizophrenia.

Olanzapine-Related Somnambulism: A Systematic Review of Literature and a Case Report of Anorexia Nervosa

BACKGROUND

Somnambulism, or sleepwalking (SW), is one of the most common forms of arousal parasomnias. It is characterized by different complex motor behaviors leading to unwanted movements in bed or walking during sleep. It can be the consequence of psychological stress, abnormal breathing during sleep, high fever, or drug adverse effects. There is evidence of an association between antipsychotic treatment, including olanzapine, and SW.

METHODS

We present the case of a patient experiencing treatment-resistant anorexia nervosa whose somnambulism re-exacerbated after the addition of a low dose of olanzapine, following the CARE (CAse REport) Statement and Checklist. We also conducted a systematic review of the literature on olanzapine-induced somnambulism following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, PsychINFO, and the Cochrane Library databases were independently reviewed up to January 2021 for articles reporting olanzapine-related somnambulism cases, without language or time restriction.

RESULTS

We describe a case of somnambulism in a patient initially admitted to our hospital for anorexia nervosa and treated with a low dose of olanzapine. This is the first case of SW induced by olanzapine in eating disorders to be reported. Up-to-date olanzapine-related somnambulism was described in 8 patients experiencing psychiatric disorders (ie, schizophrenia and bipolar disorder).

CONCLUSIONS

To provide a reliable estimate of incidence and prevalence for olanzapine-related somnambulism, large-scale, pharmacovigilance studies are required, to allow for comparisons of overall clinical characteristics, outcomes, including time to recovery, between different treatment options. Clinician awareness should be enhanced, and attention should be given to such infrequent adverse effects associated with antipsychotics.

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.

Candidate symptomatic markers for predicting violence in schizophrenia: A cross-sectional study of 7711 patients in a Chinese population

OBJECTIVE

Violent behaviour is an alarming problem among schizophrenia patients. The effects of historical, clinical, and pathological risk factors for violence have been investigated by multiple studies, but consensus has not been achieved. As psychotic symptoms are more direct and intuitive indicators for violence, identifying robustly associated symptoms is a crucial part of the future prediction and precise management of violent patients in clinics. This study aims to identify the psychotic symptoms correlated with violence among schizophrenia patients in a Chinese population.

METHODS

In this cross-sectional study, the medical records of 7711 schizophrenia patients (4711 in the discovery set and 3000 in the validation set) were collected from 1998 to 2010. Their psychotic symptoms were extracted, and the patients were divided into violent and non-violent groups. Multivariate logistic analysis was applied to identify symptoms associated with violence in the discovery set.

RESULTS

Eight psychotic symptoms were found to be significantly correlated with violence in schizophrenia. "Destruction of property", "verbal aggression" and "insomnia" increased the risk of violence, while "flat affect", "delusion of persecution", "auditory hallucination", "vagueness of thought" and "poverty of thought" decreased the risk of violence. The regression model was evaluated by receiver operating characteristic (ROC) analysis for its discriminatory performance, achieving area under curve (AUC) values of 0.887 in the discovery sample set and 0.824 in the validation sample set.

CONCLUSIONS

The correlated symptoms identified by this study can serve as future candidate predictors for violence in schizophrenia, paving the way for precise management of schizophrenia patients in clinics.

Effect of Haloperidol and Risperidone on Serum Melatonin and GAP-43 in Patients with Schizophrenia: A Prospective Cohort Study

OBJECTIVE

Serum melatonin, a biomarker of circadian rhythm, can upregulate Growth-associated protein 43 (GAP-43) which is involved in neural regeneration and plasticity. The present study was conducted to investigate the adequacy of the first-line antipsychotic drugs to improve sleep and circadian rhythm disruptions by assessing the effect of haloperidol and risperidone on serum melatonin and GAP-43 in schizophrenia.

METHODS

In this cohort study, 100 schizophrenic patients were recruited, and clinical evaluations were done using the Positive and Negative Syndrome Scale (PANSS) and the Pittsburgh sleep quality index (PSQI). The patients with predominantly positive symptoms taking haloperidol (Group I) and patients with predominantly negative symptoms taking risperidone (Group II) were admitted and serum melatonin, arylalkylamine N-acetyltransferase, GAP-43 and urinary melatonin were estimated. After 8 weeks, all clinical and biochemical parameters were repeated.

RESULTS

Serum melatonin (2:00 hours) was significantly decreased in both haloperidol (2.42; 95% confidence interval [95% CI]: 0.67-4.17; p = 0.008) and risperidone group (3.40; 95% CI: 0.54-6.25; p = 0.021). Urinary melatonin was significantly decreased in both haloperidol (p = 0.005) and risperidone group (p = 0.014). PSQI score was significantly increased in both haloperidol (p = 0.001) and risperidone group (p = 0.003). Serum GAP-43 was significantly decreased in both haloperidol and risperidone group (p < 0.001). PANSS decreased significantly in both the groups and there was a significant negative correlation between serum melatonin at 2:00 hours and PANSS (r = -0.5) at baseline.

CONCLUSION

Monotherapy with haloperidol and risperidone can achieve symptomatic improvement but cannot improve sleep and circadian rhythm disturbances in schizophrenia.

Frequent Marijuana or Alcohol Use in Low-Income Emerging Adults: Impact of Adverse Life Experiences

The transition to adulthood may be especially difficult for those who use drugs and alcohol regularly. While research clearly links adverse childhood experiences (ACEs) with later substance use, many studies have explored only a limited range of ACEs, and have focused on the number instead of specific types of ACE. Objectives: The current study examined the role of ACEs on the likelihood of frequent marijuana and alcohol use among a community sample of emerging adults (N = 185). This research builds on and extends previous work by focusing on a low-income sample, examining specific types of ACEs, and expanding categories to include some less studied ACEs. Logistic regression models examined the relationships between ACEs and frequent alcohol or marijuana use. Results: The emerging adults in the current sample experienced many ACEs in childhood, and roughly a third reported frequent (defined as using once a week or more for the past 90 days) alcohol or marijuana use. ACEs associated with both frequent marijuana and alcohol use were time spent in foster care, childhood emotional abuse, and having a close family member or friend who died violently. Alcohol use was further predicted by childhood sexual abuse and witnessing a serious injury or death, while marijuana use was further predicted by childhood physical abuse. Conclusions: Findings highlight the importance of thoroughly assessing for ACEs when addressing substance use issues in young adults. The negative impact of being in foster care may be overlooked as a trauma beyond the experiences that contributed to entering care.

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.

Identifying emerging mental illness utilizing search engine activity: A feasibility study

Mental illness often emerges during the formative years of adolescence and young adult development and interferes with the establishment of healthy educational, vocational, and social foundations. Despite the severity of symptoms and decline in functioning, the time between illness onset and receiving appropriate care can be lengthy. A method by which to objectively identify early signs of emerging psychiatric symptoms could improve early intervention strategies. We analyzed a total of 405,523 search queries from 105 individuals with schizophrenia spectrum disorders (SSD, N = 36), non-psychotic mood disorders (MD, N = 38) and healthy volunteers (HV, N = 31) utilizing one year's worth of data prior to the first psychiatric hospitalization. Across 52 weeks, we found significant differences in the timing (p<0.05) and frequency (p<0.001) of searches between individuals with SSD and MD compared to HV up to a year in advance of the first psychiatric hospitalization. We additionally identified significant linguistic differences in search content among the three groups including use of words related to sadness and perception, use of first and second person pronouns, and use of punctuation (all p<0.05). In the weeks before hospitalization, both participants with SSD and MD displayed significant shifts in search timing (p<0.05), and participants with SSD displayed significant shifts in search content (p<0.05). Our findings demonstrate promise for utilizing personal patterns of online search activity to inform clinical care.

Do sleep disturbances contribute to cognitive impairments in schizophrenia spectrum and bipolar disorders?

Sleep disturbances and cognitive impairments are both frequent across psychotic disorders, with debilitating effects on functioning and quality of life. This study aims to investigate if sleep disturbances are related to cognitive impairments in schizophrenia spectrum (SCZ) and bipolar disorders (BD), if this relationship varies between different sleep disturbances (insomnia, hypersomnia or delayed sleep phase (DSP)) and lastly, if this relationship differs between clinical groups and healthy controls (HC). We included 797 patients (SCZ = 457, BD = 340) from the Norwegian Centre for Mental Disorders Research (NORMENT) study in Norway. Sleep disturbances were based on items from the Inventory of Depressive Symptoms-Clinician rated scale (IDS-C). Their relationship with several cognitive domains was tested using separate ANCOVAs. A three-way between-groups ANOVA was conducted to test if the relationship with cognitive impairments varies between different sleep disturbances. These analyses revealed significantly poorer processing speed and inhibition in those with any sleep disturbance versus those without, also after adjusting for several covariates. The relationship between sleep disturbances and cognition was similar across SCZ and BD, and there were significant effects of insomnia and hypersomnia on both processing speed and inhibition. No association between sleep disturbances and cognition was found in HC. Sleep disturbances contribute to cognitive impairments in psychotic disorders. Processing speed and inhibition is poorer in patients with sleep disturbances. Impairments in these domains are related to insomnia and hypersomnia. These findings suggest that treating sleep disturbances is important to protect cognitive functioning, alongside cognitive remediation in psychotic disorders.

Circadian rhythm disruption and mental health

Circadian rhythms are internal manifestations of the solar day that permit adaptations to predictable environmental temporal changes. These ~24-h rhythms are controlled by molecular clockworks within the brain that are reset daily to precisely 24 h by exposure to the light-dark cycle. Information from the master clock in the mammalian hypothalamus conveys temporal information to the entire body via humoral and neural communication. A bidirectional relationship exists between mood disorders and circadian rhythms. Mood disorders are often associated with disrupted circadian clock-controlled responses, such as sleep and cortisol secretion, whereas disruption of circadian rhythms via jet lag, night-shift work, or exposure to artificial light at night, can precipitate or exacerbate affective symptoms in susceptible individuals. Evidence suggests strong associations between circadian rhythms and mental health, but only recently have studies begun to discover the direct interactions between the circadian system and mood regulation. This review provides an overview of disrupted circadian rhythms and the relationship to behavioral health and psychiatry. The focus of this review is delineating the role of disruption of circadian rhythms on mood disorders using human night shift studies, as well as jet lag studies to identify links. We also review animal models of disrupted circadian rhythms on affective responses. Lastly, we propose low-cost behavioral and lifestyle changes to improve circadian rhythms and presumably behavioral health.

Sleep disturbances in schizophrenia spectrum and bipolar disorders - a transdiagnostic perspective

BACKGROUND

Sleep disturbances are prevalent in severe mental disorders but their type and frequency across diagnostic categories has not been investigated in large scale studies.

METHODS

Participants with Schizophrenia spectrum disorders (SCZ, (N = 617)), Bipolar disorders (BD, (N = 440)), and Healthy Controls (HC, (N = 173)) were included in the study. Sleep disturbances (insomnia, hypersomnia and delayed sleep phase) were identified based on items from the Inventory of Depressive Symptoms - Clinician rated scale. Clinical symptoms were assessed with the Positive and Negative Syndrome scale and level of functioning with the Global assessment of Functioning scale.

RESULTS

The rate of any sleep disturbance was 78% in SZ, 69% in BD and 39% in HC. Insomnia was the most frequently reported sleep disturbance across all groups. Both diagnostic groups reported significantly more of any sleep disturbances than HC (P < 0.001). Having a sleep disturbance was associated with more severe negative and depressive symptoms and with lower functioning across diagnostic groups (P < 0.001, η² = 0.0071). Hypersomnia was the only sleep disturbance associated with previous treatment history.

CONCLUSION

Sleep disturbances, including insomnia, hypersomnia and delayed sleep phase, are frequent in SCZ and BD, and associated with more severe clinical symptomatology across diagnostic groups. This suggests that sleep disturbance is a clinically relevant transdiagnostic phenomenon.

The effect of cognitive behavioral therapy for insomnia in schizophrenia patients with sleep Disturbance: A non-randomized, assessor-blind trial

This non-randomized, assessor blind study evaluated the effects of cognitive behavioral therapy for insomnia (CBT-I) delivered in a group format on insomnia symptoms as well as psychotic, depressive, and anxiety symptoms in schizophrenia patients (n = 63) recruited from residential or rehabilitative facilities in Seoul, South Korea. Thirty-one patients received four sessions of CBT-I in groups of 2-9 patients in addition to usual care, while the control group (n = 32) received no additional intervention. The Insomnia Severity Index (ISI) and Pittsburgh Sleep Quality Index (PSQI), Psychotic Symptoms Rating Scale (PSYRATS), Anxiety Sensitivity Index (ASI), and Beck Depression Inventory (BDI) were administered at baseline, week 4, and week 8. Both groups showed significant time-group interactions on the ISI and PSQI. Post hoc testing showed that, compared to the control group, the CBT-I group showed significant reductions in ISI and PSQI at both week 4 and week 8. For the PSYRATS, ASI, and BDI scores, the CBT-I and control groups showed significant time-group interactions, but post hoc testing revealed no significant group differences at either week 4 or week 8. Therefore, CBT-I was effective for reducing insomnia symptoms in patients with schizophrenia and the effect lasted for 4 weeks after the intervention.

Abnormal Sleep Spindles, Memory Consolidation, and Schizophrenia

There is overwhelming evidence that sleep is crucial for memory consolidation. Patients with schizophrenia and their unaffected relatives have a specific deficit in sleep spindles, a defining oscillation of non-rapid eye movement (NREM) Stage 2 sleep that, in coordination with other NREM oscillations, mediate memory consolidation. In schizophrenia, the spindle deficit correlates with impaired sleep-dependent memory consolidation, positive symptoms, and abnormal thalamocortical connectivity. These relations point to dysfunction of the thalamic reticular nucleus (TRN), which generates spindles, gates the relay of sensory information to the cortex, and modulates thalamocortical communication. Genetic studies are beginning to provide clues to possible neurodevelopmental origins of TRN-mediated thalamocortical circuit dysfunction and to identify novel targets for treating the related memory deficits and symptoms. By forging empirical links in causal chains from risk genes to thalamocortical circuit dysfunction, spindle deficits, memory impairment, symptoms, and diagnosis, future research can advance our mechanistic understanding, treatment, and prevention of schizophrenia.

Toxoplasma gondii IgG associations with sleep-wake problems, sleep duration and timing

Background:

Evidence links Toxoplasmagondii (T. gondii), a neurotropic parasite, with schizophrenia, mood disorders and suicidal behavior, all of which are associated and exacerbated by disrupted sleep. Moreover, low-grade immune activation and dopaminergic overstimulation, which are consequences of T. gondii infection, could alter sleep patterns and duration.

Methods:

Sleep data on 833 Amish participants [mean age (SD) = 44.28 (16.99) years; 59.06% women] were obtained via self-reported questionnaires that assessed sleep problems, duration and timing. T. gondii IgG was measured with ELISA. Data were analyzed using multivariable logistic regressions and linear mixed models, with adjustment for age, sex and family structure.

Results:

T. gondii seropositives reported less sleep problems (p < 0.005) and less daytime problems due to poor sleep (p < 0.005). Higher T. gondii titers were associated with longer sleep duration (p < 0.05), earlier bedtime (p< 0.005) earlier mid-sleep time (p < 0.05).

Conclusions:

It seems unlikely that sleep mediates the previously reported associations between T. gondii and mental illness. Future longitudinal studies with objective measures are necessary to replicate our findings.

Sleep onset insomnia, daytime sleepiness and sleep duration in relationship to Toxoplasma gondii IgG seropositivity and serointensity

Toxoplasma gondii (T. gondii) infects central nervous tissue and is kept in relative dormancy by a healthy immune system. Sleep disturbances have been found to precipitate mental illness, suicidal behavior and car accidents, which have been previously linked to T. gondii as well. We speculated that if sleep disruption, particularly insomnia, would mediate, at least partly, the link between T. gondii infection and related behavioral dysregulation, then we would be able to identify significant associations between sleep disruption and T. gondii. The mechanisms for such an association may involve dopamine (DA) production by T. gondii, or collateral effects of immune activation necessary to keep T. gondii in check. Sleep questionnaires from 2031 Old Order Amish were analyzed in relationship to T. gondii-IgG antibodies measured by enzyme-linked immunosorbent assay (ELISA). Toxoplasma gondii seropositivity and serointensity were not associated with any of the sleep latency variables or Epworth Sleepiness Scale (ESS). A secondary analysis identified, after adjustment for age group, a statistical trend toward shorter sleep duration in seropositive men (p = 0.07). In conclusion, it is unlikely that sleep disruption mediates links between T. gondii and mental illness or behavioral dysregulation. Trending gender differences in associations between T. gondii and shorter sleep need further investigation.

Adolescents at clinical-high risk for psychosis: Circadian rhythm disturbances predict worsened prognosis at 1-year follow-up

BACKGROUND

Individuals with psychotic disorders experience disruptions to both the sleep and circadian components of the sleep/wake cycle. Recent evidence has supported a role of sleep disturbances in emerging psychosis. However, less is known about how circadian rhythm disruptions may relate to psychosis symptoms and prognosis for adolescents with clinical high-risk (CHR) syndromes. The present study examines circadian rest/activity rhythms in CHR and healthy control (HC) youth to clarify the relationships among circadian rhythm disturbance, psychosis symptoms, psychosocial functioning, and the longitudinal course of illness.

METHODS

Thirty-four CHR and 32 HC participants were administered a baseline evaluation, which included clinical interviews, 5days of actigraphy, and a sleep/activity diary. CHR (n=29) participants were re-administered clinical interviews at a 1-year follow-up assessment.

RESULTS

Relative to HC, CHR youth exhibited more fragmented circadian rhythms and later onset of nocturnal rest. Circadian disturbances (fragmented rhythms, low daily activity) were associated with increased psychotic symptom severity among CHR participants at baseline. Circadian disruptions (lower daily activity, rhythms that were more fragmented and/or desynchronized with the light/dark cycle) also predicted severity of psychosis symptoms and psychosocial impairment at 1-year follow-up among CHR youth.

CONCLUSIONS

Circadian rhythm disturbances may represent a potential vulnerability marker for emergence of psychosis, and thus, rest/activity rhythm stabilization has promise to inform early-identification and prevention/intervention strategies for CHR youth. Future studies with longer study designs are necessary to further examine circadian rhythms in the prodromal period and rates of conversion to psychosis among CHR teens.

Low doses of mirtazapine or quetiapine for transient insomnia: A randomised, double-blind, cross-over, placebo-controlled trial

Low doses of the antidepressant mirtazapine or the neuroleptic quetiapine are often prescribed off-label for insomnia. However, studies on the effects on sleep and hangover effects the following day are scarce. In this randomised, double-blind, cross-over, placebo-controlled trial, the influence of 7.5 mg mirtazapine and 50 mg quetiapine on both normal sleep and sleep disturbed by acoustic stress (traffic noise) as a model for transient insomnia was assessed. Additionally, hangover effects on next-day alertness and cognitive functioning were examined. A total of 19 healthy men without sleep complaints completed three treatment sessions, each session consisting of three consecutive nights in one of the mirtazapine, quetiapine or placebo conditions. Sleep was assessed using polysomnography and the Leeds Sleep Evaluation Questionnaire. Daytime sleepiness and cognitive functioning were assessed using the Leeds Sleep Evaluation Questionnaire, Karolinska Sleepiness Scale, Digit Symbol Substitution Task, Psychomotor Vigilance Task and an addition task. Under acoustic stress, both mirtazapine and quetiapine increased total sleep time by half an hour and reduced the number of awakenings by 35-40% compared to placebo. While quetiapine specifically increased the duration of non-rapid eye movement sleep, stage N2, mirtazapine mainly increased deep sleep stage N3. Subjects reported that both mirtazapine and quetiapine eased getting to sleep and improved sleep quality. Both drugs caused daytime sleepiness and lessened sustained attention. These findings support the use of low doses of mirtazapine and quetiapine for the treatment of insomnia. Further prospective studies on the long-term effects regarding effectiveness and adverse effects are needed.

Schizophrenia and sleep disorders: links, risks, and management challenges

Schizophrenia is a major psychiatric disorder that has a massive, long-lasting negative impact on the patients as well as society. While positive symptoms (i.e., delusions and hallucinations), negative symptoms (i.e., anhedonia, social withdrawal), and cognitive impairments are traditionally considered the most prominent features of this disorder, the role of sleep and sleep disturbances has gained increasing prominence in clinical practice. Indeed, the vast majority of patients with schizophrenia report sleep abnormalities, which tend to precede illness onset and can predict an acute exacerbation of psychotic symptoms. Furthermore, schizophrenia patients often have a comorbid sleep disorder, including insomnia, obstructive sleep apnea, restless leg syndrome, or periodic limb movement disorder. Despite accumulating data, the links between sleep disorders and schizophrenia have not been thoroughly examined, in part because they are difficult to disentangle, as numerous factors contribute to their comorbidity, including medication status. Additionally, sleep disorders are often not the primary focus of clinicians treating this population, despite studies suggesting that comorbid sleep disorders carry their own unique risks, including worsening of psychotic symptoms and poorer quality of life. There is also limited information about effective management strategies for schizophrenia patients affected by significant sleep disturbances and/or sleep disorders. To begin addressing these issues, the present review will systematically examine the literature on sleep disorders and schizophrenia, focusing on studies related to 1) links between distinct sleep disorders and schizophrenia; 2) risks unique to patients with a comorbid sleep disorder; and 3) and management challenges and strategies.

Reduced Sleep Spindles in Schizophrenia: A Treatable Endophenotype That Links Risk Genes to Impaired Cognition?

Although schizophrenia (SZ) is defined by waking phenomena, abnormal sleep is a common feature. In particular, there is accumulating evidence of a sleep spindle deficit. Sleep spindles, a defining thalamocortical oscillation of non-rapid eye movement stage 2 sleep, correlate with IQ and are thought to promote long-term potentiation and enhance memory consolidation. We review evidence that reduced spindle activity in SZ is an endophenotype that impairs sleep-dependent memory consolidation, contributes to symptoms, and is a novel treatment biomarker. Studies showing that spindles can be pharmacologically enhanced in SZ and that increasing spindles improves memory in healthy individuals suggest that treating spindle deficits in patients with SZ may improve cognition. Spindle activity is highly heritable, and recent large-scale genome-wide association studies have identified SZ risk genes that may contribute to spindle deficits and illuminate their mechanisms. For example, the SZ risk gene CACNA1I encodes a calcium channel that is abundantly expressed in the thalamic spindle generator and plays a critical role in spindle activity based on a mouse knockout. Future genetic studies of animals and humans can delineate the role of this and other genes in spindles. Such cross-disciplinary research, by forging empirical links in causal chains from risk genes to proteins and cellular functions to endophenotypes, cognitive impairments, symptoms, and diagnosis, has the potential to advance the mechanistic understanding, treatment, and prevention of SZ. This review highlights the importance of deficient sleep-dependent memory consolidation among the cognitive deficits of SZ and implicates reduced sleep spindles as a potentially treatable mechanism.

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.