Do sleep disturbances and psychotic-like experiences in adolescence share genetic and environmental influences?

The Effect of Breathing and Relaxation Exercises Training on Psychological Well-Being and Sleep Quality in Individuals Diagnosed With Schizophrenia: A Randomized Controlled Study

This study was conducted to determine the effect of breathing and relaxation exercises training on psychological well-being and sleep quality in individuals diagnosed with schizophrenia. This study was conducted at a community mental health center between October 2022 and April 2023 as a randomized controlled study with a pretest-posttest control group. The study's participants were 64 individuals diagnosed with schizophrenia (31 in the experimental group and 33 in the control group). The Descriptive Characteristics Form, the Psychological Well-being Scale, and the Pittsburg Sleep Quality Index were used to collect data. The individuals in the experimental group underwent 6 sessions of breathing and relaxation exercises training in the form of group training, and no training was applied to the individuals in the control group. It was determined that the individuals in the experimental group had an increase in the total mean score of psychological well-being and a decrease in the total mean score of sleep quality after breathing and relaxation exercise training. In addition, a statistically significant difference was found between the posttest psychological well-being and sleep quality total mean scores of the experimental and control groups ( P < .05). It can be said that breathing and relaxation exercises training can be used as an effective intervention to increase the psychological well-being and sleep quality of individuals diagnosed with schizophrenia and can be used in addition to pharmacological treatment.

Sleep and circadian difficulties in schizophrenia: presentations, understanding, and treatment

It is common in mental health care to ask about people's days but comparatively rare to ask about their nights. Most patients diagnosed with schizophrenia struggle at nighttime. The next-day effects can include a worsening of psychotic experiences, affective disturbances, and inactivity, which in turn affect the next night's sleep. Objective and subjective cognitive abilities may be affected too. Patients commonly experience a mix of sleep difficulties in a night and across a week. These difficulties include trouble falling asleep, staying asleep, or sleeping at all; nightmares and other awakenings; poor-quality sleep; oversleeping; tiredness; sleeping at the wrong times; and problems establishing a regular sleep pattern. The patient group is also more vulnerable to obstructive sleep apnea and restless legs syndrome. We describe in this article how the complex presentation of non-respiratory sleep difficulties arises from variation across five factors: timing, mental state, need for sleep, self-care, and environment. We set out 10 illustrative patterns of such difficulties experienced by patients with non-affective psychosis. These sleep problems are eminently treatable with intensive psychological therapy delivered over approximately eight sessions. We describe key techniques and their typical order of implementation by presentation. Sleep problems are an important issue for patients. Giving them the therapeutic attention patients often desire brings both real clinical benefits and improves views of services. Treatment is also very likely to lessen psychotic experiences and mood disturbances while improving daytime functioning and quality of life. Tackling sleep difficulties can be a route toward the successful treatment of psychosis.

Bidirectional associations between short sleep duration, insomnia symptoms, and psychotic-like experiences in adolescents

This study investigates the prospective associations between short sleep duration, insomnia symptoms, and psychotic-like experiences (PLEs) in a large sample of Chinese adolescents. This study utilized a three-timepoint repeated cross-sectional survey with two nested longitudinal subsamples. A total of 17,722 adolescents were assessed at baseline (April 21 to May 12, 2021) and six months later (December 17 to 26, 2021). Out of these, 15,694 adolescents provided complete responses to the questions at baseline and one year later (May 17 - June 6, 2022). A self-administered questionnaire was used to measure sample characteristics (at baseline), sleep duration, insomnia symptoms, and PLEs (at each assessment), and negative life events (at two follow-ups). Baseline short sleep duration and insomnia symptoms predicted frequent PLEs at both follow-up assessments. Additionally, baseline frequent PLEs also predicted insomnia symptoms at six months and one year later. However, when controlling for confounders, PLEs at baseline only predicted short sleep duration at six months, and not at one year. This study reveals bidirectional prospective relationships between short sleep duration, insomnia symptoms, and PLEs, even after controlling for covariates. Therefore, it is crucial to assess both sleep patterns and PLEs in order to promote optimal sleep and mental health among adolescents.

Sleep and paranoia: A systematic review and meta-analysis

BACKGROUND

Sleep dysfunction commonly co-occurs with paranoia and is hypothesised to be a contributory causal mechanism in its development and maintenance.

OBJECTIVES

To systematically review and quantitatively evaluate the evidence for the relationship between sleep dysfunction and paranoia across the spectrum of severity.

METHOD

A systematic search was conducted to identify studies investigating the relationship between aspects of sleep and paranoia across clinical and non-clinical groups. A random effects model using a Fisher r-to-z transformed correlation coefficient was used for meta-analysis.

RESULTS

45 studies were included in the review and 14 in the meta-analysis. The literature supports a small-to-moderate association (r = 0.30, 95 % CI: 0.16-0.40 for the seven studies using the most robust measures) with significant heterogeneity among studies but no evidence of publication bias. There is evidence that the relationship is to some extent causal, with sleep disruption leading to increased paranoia, though there is also some evidence of a bi-directional relationship. Negative affect is frequently seen as a mediator of this relationship.

CONCLUSION

This review for the first time examines the significant relationship between sleep and paranoia individually. Studies are needed that further assess the potential for early intervention of sleep dysfunction in those experiencing paranoia.

Impaired Sleep Mediates the Relationship Between Interpersonal Trauma and Subtypes of Delusional Ideation

BACKGROUND AND HYPOTHESIS

Trauma is a robust risk factor for delusional ideation. However, the specificity and processes underlying this relationship are unclear. Qualitatively, interpersonal traumas (i.e., trauma caused by another person) appear to have a specific relationship with delusional ideation, particularly paranoia, given the commonality of social threat. However, this has not been empirically tested and the processes by which interpersonal trauma contributes to delusional ideation remain poorly understood. Given the role of impaired sleep in both trauma and delusional ideation, it may be a critical mediator between these variables. We hypothesized that interpersonal trauma, but not non-interpersonal trauma, would be positively related to subtypes of delusional ideation, especially paranoia, and that impaired sleep would mediate these relationships.

STUDY DESIGN

In a large, transdiagnostic community sample (N = 478), an exploratory factor analysis of the Peter's Delusion Inventory identified three subtypes of delusional ideation, namely magical thinking, grandiosity, and paranoia. Three path models, one for each subtype of delusional ideation, tested whether interpersonal trauma and non-interpersonal trauma were related to subtypes of delusional ideation, and impaired sleep as a mediating variable of interpersonal trauma.

STUDY RESULTS

Paranoia and grandiosity were positively related to interpersonal trauma and unrelated to non-interpersonal trauma. Furthermore, these relationships were significantly mediated by impaired sleep, which appeared strongest for paranoia. In contrast, magical thinking was unrelated to traumatic experiences.

CONCLUSIONS

These findings support a specific relationship between interpersonal trauma and paranoia as well as grandiosity, with impaired sleep appearing as an important process by which interpersonal trauma contributes to both.

Alexithymia is associated with insomnia in Chinese patients with schizophrenia

Background

Sleep disorders are prevalent among patients with schizophrenia and are associated with several negative consequences. Although, researchers have recently suggested that sleep disorders have a close correlation with alexithymia, and schizophrenia also has a strong correlation with alexithymia, there have been few studies on the relationships between schizophrenia, sleep disorders and alexithymia. Therefore, this study aimed to explore the relationships between psychiatric symptoms, alexithymia and sleep problems in patients with schizophrenia so as to provide a reference for the clinical treatment of this comorbidity.

Methods

In total, 977 patients with schizophrenia were recruited for this study. The Insomnia Severity Index (ISI) was used to assess sleep disorders, and the Positive and Negative Syndrome Scale (PANSS), Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and Toronto Alexithymia Scale (TAS) were used to evaluate clinical symptoms, cognitive functions and the ability to express emotion, respectively.

Results

The results indicated that the PANSS subscales (G-subscore) and TAS group were risk factors for insomnia in schizophrenia patients (all p < 0.05). The mediation model showed the standardized path coefficients from schizophrenia to alexithymia (β = 0.104, p < 0.001) and from alexithymia to insomnia (β = 0.038, p < 0.001) were statistically significant.

Conclusion

The results of this study indicated that alexithymia is associated with sleep disturbance in patients with schizophrenia. These findings may provide a new avenue for the treatment of schizophrenia patients with sleep disorders.

Potential genetic and epigenetic mechanisms in insomnia: A systematic review

Insomnia is a stress-related sleep disorder conceptualised within a diathesis-stress framework, which it is thought to result from predisposing factors interacting with precipitating stressful events that trigger the development of insomnia. Among predisposing factors genetics and epigenetics may play a role. A systematic review of the current evidence for the genetic and epigenetic basis of insomnia was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) system. A total of 24 studies were collected for twins and family heritability, 55 for genome-wide association studies, 26 about candidate genes for insomnia, and eight for epigenetics. Data showed that insomnia is a complex polygenic stress-related disorder, and it is likely to be caused by a synergy of genetic and environmental factors, with stress-related sleep reactivity being the important trait. Even if few studies have been conducted to date on insomnia, epigenetics may be the framework to understand long-lasting consequences of the interaction between genetic and environmental factors and effects of stress on the brain in insomnia. Interestingly, polygenic risk for insomnia has been causally linked to different mental and medical disorders. Probably, by treating insomnia it would be possible to intervene on the effect of stress on the brain and prevent some medical and mental conditions.

Sub-types of insomnia in adolescents: Insights from a quantitative/molecular twin study

Background

Insomnia with short sleep duration has been postulated as more severe than that accompanied by normal/long sleep length. While the short duration subtype is considered to have greater genetic influence than the other subtype, no studies have addressed this question. This study aimed to compare these subtypes in terms of: (1) the heritability of insomnia symptoms; (2) polygenic scores (PGS) for insomnia symptoms and sleep duration; (3) the associations between insomnia symptoms and a wide variety of traits/disorders.

Methods

The sample comprised 4000 pairs of twins aged 16 from the Twins Early Development Study. Twin models were fitted to estimate the heritability of insomnia in both groups. PGS were calculated for self-reported insomnia and sleep duration and compared among participants with short and normal/long sleep duration.

Results

Heritability was not significantly different in the short sleep duration group (A = 0.13 [95%CI = 0.01, 0.32]) and the normal/long sleep duration group (A = 0.35 [95%CI = 0.29, 0.40]). Shared environmental factors accounted for a substantial proportion of the variance in the short sleep duration group (C = 0.19 [95%CI = 0.05, 0.32]) but not in the normal/long sleep duration group (C = 0.00 [95%CI = 0.00, 0.04]). PGS did not differ significantly between groups although results were in the direction expected by the theory. Our results also showed that insomnia with short (as compared to normal/long) sleep duration had a stronger association with anxiety and depression (p < .05)-although not once adjusting for multiple testing.

Conclusions

We found mixed results in relation to the expected differences between the insomnia subtypes in adolescents. Future research needs to further establish cut-offs for 'short' sleep at different developmental stages and employ objective measures of sleep.

Behaviour genetics and sleep: A narrative review of the last decade of quantitative and molecular genetic research in humans

During the last decade quantitative and molecular genetic research on sleep has increased considerably. New behavioural genetics techniques have marked a new era for sleep research. This paper provides a summary of the most important findings from the last ten years, on the genetic and environmental influences on sleep and sleep disorders and their associations with health-related variables (including anxiety and depression) in humans. In this review we present a brief summary of the main methods in behaviour genetic research (such as twin and genome-wide association studies). We then discuss key research findings on: genetic and environmental influences on normal sleep and sleep disorders, as well as on the association between sleep and health variables (highlighting a substantial role for genes in individual differences in sleep and their associations with other variables). We end by discussing future lines of enquiry and drawing conclusions, including those focused on problems and misconceptions associated with research of this type. In this last decade our knowledge about genetic and environmental influences on sleep and its disorders has expanded. Both, twin and genome-wide association studies show that sleep and sleep disorders are substantially influenced by genetic factors and for the very first time multiple specific genetic variants have been associated with sleep traits and disorders.

Sleep disturbance is predictive of psychotic-like experiences among adolescents: A two-wave longitudinal survey

PURPOSE

Psychotic-like experiences (PLEs) are prevalent among adolescents and are the most significant predictor of future mental disorders. This study aims to examine the cross-sectional and longitudinal associations between sleep disturbance and PLEs in a large cohort of adolescents.

METHODS

The 17,722 adolescents in our study were assessed from April 21 to May 12, 2021 (Time 1, T1) and again 6 months later from December 17 to 26, 2021 (Time 2, T2). The Youth Self Rating Insomnia Scale and 8-item Positive Subscale of the Community Assessment of Psychic Experiences were used to assess sleep and PLEs, respectively. Sample characteristics and depression were also evaluated at T1, and negative life events were measured at T2. Sleep duration ≤6 h per night was considered as sleep deprivation, and sleep disturbance was defined as having insomnia or poor sleep quality.

RESULTS

The prevalence of sleep disturbance and frequent PLEs at T1 were 14.1% and 14.5%, respectively. Sleep disturbance and sleep deprivation at T1 were significantly associated with increased risk for PLEs at T2 after adjusting for sample characteristics, depression, and negative life events. Furthermore, sleep disturbance and sleep deprivation also predicted the new onset and persistence of PLEs.

CONCLUSION

Sleep disturbance predicts the development and persistence of PLEs. Early assessment and treatment of sleep disturbance may therefore contribute to a comprehensive strategy for the successful prevention and treatment of PLEs in adolescents.

Resilience buffers the association between sleep disturbance and psychotic-like experiences in adolescents

BACKGROUND

Sleep disturbance may cause psychotic-like experiences (PLEs). The present study aimed to exam their rate of co-occurrence and investigate whether resilience buffers the association.

METHODS

A total of 50,625 junior high school students were assessed using the self-compiled socio-demographics and sleep questionnaires, 8-item Positive Subscale of the Community Assessment of Psychic Experiences, 10-item Connor-Davidson Resilience Scale, Patient Health Questionnaire and Generalized Anxiety Disorder Questionnaire.

RESULTS

In this sample, 15.8% participants had frequent PLEs in the past month, where 40.1% exhibited comorbid sleep disturbance. Sleep disturbance positively associated with the onset of frequent PLEs, after adjusting for socio-demographics, depression and anxiety. Moderation analysis showed resilience buffers the association between sleep disturbance and PLEs, with a higher level of resilience, the positive effect of sleep disturbance on PLEs would be diminished to a greater extent.

CONCLUSIONS

These findings suggested that early attention should be drawn to adolescents with sleep disturbance. Intervention strategies should be enhancing resilience, increasing sleep duration and improving sleep quality.

Correlates of psychotic like experiences (PLEs) during Pandemic: An online study investigating a possible link between the SARS-CoV-2 infection and PLEs among adolescents

BACKGROUND

This study investigated whether SARS-CoV-2 infection, depression, anxiety, sleep problems, cigarette, alcohol, drug usage contribute to psychotic-like experiences (PLEs) among adolescents during the pandemic. We also aimed to explore whether baseline inflammatory markers or the number of SARS-CoV-2-related symptoms are associated with PLEs, and the latter is mediated by internalizing symptoms.

METHODS

Altogether, 684 adolescents aged 12-18 (SARS-CoV-2 group n = 361, control group (CG) n = 323) were recruited. The Community Assessment of Psychic Experiences-42-Positive Dimension (CAPE-Pos), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Pittsburg Sleep Quality Index (PSQI) questionnaires were completed by all volunteers using an online survey. C-reactive Protein and hemogram values, and SARS-CoV-2-related symptoms during the acute infection period were recorded in the SARS-CoV-2 group. Group comparisons, correlations, logistic regression, and bootstrapped mediation analyses were performed.

RESULTS

CAPE-Pos-Frequency/Stress scores were significantly higher, whereas GAD-7-Total and PSQI-Total scores were significantly lower in SARS-CoV-2 than CG. Among the SARS-CoV-2 group, monocyte count and the number of SARS-CoV-2-symptoms were positively correlated with CAPE-Pos-Frequency/Stress scores. Besides SARS-CoV-2, cigarette use, GAD-7, and PHQ-9 scores significantly contributed to the presence of at least one CAPE-Pos "often" or "almost always". PHQ-9 and GAD-7 fully mediated the relationship between the number of SARS-CoV-2 symptoms and CAPE-Pos-Frequency.

CONCLUSIONS

This study is the first to show a possible relationship between SARS-CoV-2 infection and PLEs among adolescents. Depression, anxiety, and cigarette use also contributed to PLEs. The number of SARS-Cov-2-symptoms and PLEs association was fully mediated by internalizing symptoms, but prospective studies will need to confirm this result.

Psychotic-Like Experiences Associated with Sleep Disturbance and Brain Volumes in Youth: Findings from the Adolescent Brain Cognitive Development Study

Background

Sleep disturbance is characteristic of schizophrenia and at-risk populations, suggesting a possible etiological role in psychosis. Biological mechanisms underlying associations between sleep and psychosis vulnerability are unclear, although reduced sleep-regulatory brain structure volumes are a proposed contributor. This study is the first to examine relationships between psychotic-like experiences (PLEs; subclinical symptoms reflecting psychosis vulnerability/risk), sleep, and brain volumes in youth.

Methods

Brain volumes of five sleep-related structures were examined in relation to PLEs and difficulties initiating and maintaining sleep (DIMS) in 9260 9-11 year-olds participating in the Adolescent Brain Cognitive Development (ABCD) study. Analytic models examined relationships between DIMS, PLEs, and brain volumes, as well as DIMS as a mediator of brain volume-PLEs relationships. Although sleep regulation structures (i.e., thalamus, basal forebrain, hypothalamus) were of primary interest, other potentially-relevant structures to sleep-related functioning and psychosis (i.e., hippocampus, amygdala) were also examined.

Results

PLEs were associated with increased DIMS as well as reduced volume in some, but not all, brain structures, including the thalamus and basal forebrain in children. DIMS was also associated with reduced left thalamus volume in youth. Increased DIMS partially, statistically mediated the relationship between left thalamic volume and PLEs, although the effect was relatively small.

Conclusions

Results highlight left thalamic volume as a potential neural mechanism underlying sleep disturbances and PLEs in childhood. Future studies should assess causal relationships between sleep, PLEs, and brain structure across adolescent development, interactions with other psychosis risk factors, and the role of sleep interventions in prevention of psychosis and a range of psychiatric conditions across the lifespan.

Paranoia in patients attending child and adolescent mental health services

OBJECTIVE

Paranoia may be particularly prevalent during adolescence, building on the heightened social vulnerabilities at this age. Excessive mistrust may be corrosive for adolescent social relationships, especially in the context of mental health disorders. We set out to examine the prevalence, symptom associations, and persistence of paranoia in a cohort of young people attending child and adolescent mental health services.

METHOD

A total of 301 patients (11-17 years old) completed measures of paranoia, affect, peer difficulties and behavioural problems. Clinicians also rated each participant's psychiatric symptoms. Patterns of association were examined using linear regressions and network analyses. In total, 105 patients repeated the measures several months later.

RESULTS

Most of the adolescents had affective disorders (n = 195), self-harm/suicidality (n = 82), or neurodevelopmental conditions (n = 125). Few had suspected psychosis (n = 7). Rates of paranoia were approximately double compared with previous reports from the general population. In this patient sample, 35% had at least elevated paranoia, 15% had at least moderate paranoia, and 6% had high paranoia. Paranoia had moderate associations with clinician-rated peer difficulties, self-harm, and trauma, and small associations with clinician-rated social anxiety, depression, generalised anxiety, and educational problems. Network analyses showed paranoia had the strongest unique relationship with peer difficulties. Paths from peer difficulties to anxiety, self-harm, post-traumatic stress disorder symptoms, and behavioural problems were all via paranoia. Both self-harm and post-traumatic stress disorder were solely associated with paranoia in the network. Paranoia remained persistent for three-quarters and was associated with greater psychological problems over time.

CONCLUSION

Paranoia is relatively common and persistent across a range of clinical presentations in youth. When paranoia occurs alongside emotional problems, important peer interactions may be adversely affected. Wider consideration of paranoia in adolescent patients is needed.

Actigraphic sleep and cortisol in middle childhood: A multivariate behavioral genetics model

To date, behavioral genetic studies investigated either sleep or cortisol levels in middle childhood, but not both simultaneously. Therefore, a pertinent question is the degree to which genetic factors and environmental factor contribute to the correlation between sleep and cortisol levels. To address this question, we employed the classical twin design. We measured sleep in 6-9-year-old twins (N = 436 twin pairs, “Together Unique” study) over four consecutive nights using actigraphy, and we measured morning cortisol on two consecutive days. Sleep duration, sleep efficiency, and wake episodes were used as indicators of sleep. Morning cortisol level was used as cortisol indicator. A structural equation model was fitted to estimate the contribution of additive genetic effects (A), shared (common) environmental effects, (C) and unique environmental effects (E) to phenotypic variances and covariances. Age, cohort, and sex were included as covariates. The heritability of sleep duration, sleep efficiency, and wake episodes were 52%, 45%, and 55%, respectively. Common environmental factors played no significant role. High genetic correlations between sleep duration and sleep efficiency and high genetic correlations between sleep efficiency and wake episodes were found. Shared environmental (29%) and unique environmental factors (53%) explained the variance in morning cortisol levels. Because the sleep and cortisol measures were found to be uncorrelated, we did not consider genetic and environmental contributions to the association between the sleep and cortisol measures. Our findings indicate that sleep duration, sleep efficiency, and wake episodes in children are mostly impacted by genetic factors and by unique environmental factors (including measurement error).

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Sleep duration, efficiency and wake episodes are moderately heritable.

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A high genetic correlation underlies sleep duration and sleep efficiency.

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A high genetic correlation underlies sleep efficiency and wake episodes.

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Cortisol and sleep were not (genetically) correlated.

Sleep Interventions in the Treatment of Schizophrenia and Bipolar Disorder

Due to the effects of sleep on the central nervous system, it is thought that sleep disorders have a special importance in the onset, course and treatment of psychiatric diseases. Although the negative effects of sleep problems on the occurrence, recurrence and clinical course of psychiatric disorders are well known, it is reported that clinicians do not spend enough time for sleep problems in practice. This may be related to the fact that patients underreport their complaints for various reasons, insufficient examination time, and clinicians' lack of knowledge about the importance of the subject. Pharmacotherapy, psychological and behavioral interventions are options among the therapeutic approaches to sleep problems. But, it seems that clinicians tend to prefer pharmacological approaches for the treatment of sleep problems. However, it is important to choose the appropriate treatment option with considering the method preferred by the patients, who already use many and high doses of pharmacological agents, the nature of the psychiatric disorder and the sleep problem. In this context, chronotherapeutic approaches such as bright light, sleep deprivation, interpersonal relations and social rhythm therapy, and cognitive behavioral therapy techniques adapted for patients with bipolar disorder can be used in the treatment of suitable patients. In this article, the current literature about sleep-related problems observed in patients with schizophrenia and bipolar disorder is reviewed comprehensively with presenting clinical phenotypes and treatment approaches.

Sleep duration and auditory hallucinations: Genetic correlation and two-sample Mendelian randomization study

OBJECTIVES

Previous studies have found that sleep problems are associated with psychotic experiences (PEs) across clinical designs, but many confounding factors from uncertain variables have been unclear in observational designs. The aim of the present study was to detect the genetic correlations and causal relationship between sleep-related traits and PEs using the largest current genome-wide association study (GWAS) summary statistics.

METHODS

GWAS results were obtained for positive PEs (N = 116,787-117,794) and sleep-related traits [insomnia complaints (N = 386,533), morningness (N = 345,552), sleep duration (N = 384,317), ease of getting up in the morning (N = 385,949), daytime napping (N = 386,577), daytime sleepiness (N = 386,548), and snoring (N = 359,916)]. Linkage disequilibrium score regression (LDSC) was used to investigate genetic correlations. Mendelian randomization (MR) was conducted on trait pairs with significant genetic associations.

RESULTS

We found that auditory hallucinations were significantly genetically correlated with insomnia complaints (rg = -0.27, p = 1.1 × 10^-3), sleep duration (rg = 0.21, p = 9.7 × 10^-3), and ease of getting up (rg = 0.31, p = 2 × 10^-4). Visual hallucinations and insomnia complaints were highly genetically correlated (rg = 0.36, p = 6.4 × 10^-5). Mendelian randomization indicated a unidirectional causal relationship between sleep duration with auditory hallucinations (β = -0.93, p = 7.9 × 10^-4 for sleep duration as the exposure). We used large GWAS summary statistics across the LDSC and MR programs to determine that sleep duration as exposure to increase the risk of auditory hallucinations.

CONCLUSIONS

Taken together, these findings suggest that treatment of sleep problems should be considered as a higher priority for future mental health services.

Genetic overlap and causal associations between smoking behaviours and mental health

Cigarette smoking is a modifiable behaviour associated with mental health. We investigated the degree of genetic overlap between smoking behaviours and psychiatric traits and disorders, and whether genetic associations exist beyond genetic influences shared with confounding variables (cannabis and alcohol use, risk-taking and insomnia). Second, we investigated the presence of causal associations between smoking initiation and psychiatric traits and disorders. We found significant genetic correlations between smoking and psychiatric disorders and adult psychotic experiences. When genetic influences on known covariates were controlled for, genetic associations between most smoking behaviours and schizophrenia and depression endured (but not with bipolar disorder or most psychotic experiences). Mendelian randomization results supported a causal role of smoking initiation on psychiatric disorders and adolescent cognitive and negative psychotic experiences, although not consistently across all sensitivity analyses. In conclusion, smoking and psychiatric disorders share genetic influences that cannot be attributed to covariates such as risk-taking, insomnia or other substance use. As such, there may be some common genetic pathways underlying smoking and psychiatric disorders. In addition, smoking may play a causal role in vulnerability for mental illness.

Polygenic risk scores for major psychiatric and neurodevelopmental disorders contribute to sleep disturbance in childhood: Adolescent Brain Cognitive Development (ABCD) Study

Sleep disturbance is a common symptom of psychiatric and neurodevelopmental disorders and, especially in childhood, can be a precursor to various mental disorders. However, the genetic etiology of mental illness that contributes to sleep disturbance during childhood is poorly understood. We investigated whether the polygenic features of psychiatric and neurodevelopmental disorders are associated with sleep disturbance during childhood. We conducted polygenic risk score (PRS) analyses by utilizing large-scale genome-wide association studies (GWASs) (n = 46,350-500,199) of five major psychiatric and neurodevelopmental disorders (autism spectrum disorder, schizophrenia, attention-deficit/hyperactivity disorder (ADHD), major depressive disorder (MDD), and bipolar disorder) and, additionally, anxiety disorders as base datasets. We used the data of 9- to 10-year-olds from the Adolescent Brain Cognitive Development study (n = 9683) as a target dataset. Sleep disturbance was assessed based on the Sleep Disturbance Scale for Children (SDSC) scores. The effects of PRSs for these psychiatric and neurodevelopmental disorders on the total scores and six subscale scores of the SDSC were investigated. Of the PRSs for the five psychiatric and neurodevelopmental disorders, the PRSs for ADHD and MDD positively correlated with sleep disturbance in children (ADHD: R2 = 0.0033, p = 6.19 × 10-5, MDD: R2 = 0.0042, p = 5.69 × 10-6). Regarding the six subscale scores of the SDSC, the PRSs for ADHD positively correlated with both disorders of initiating and maintaining sleep (R2 = 0.0028, p = 2.31 × 10-4) and excessive somnolence (R2 = 0.0023, p = 8.44 × 10-4). Furthermore, the PRSs for MDD primarily positively correlated with disorders of initiating and maintaining sleep (R2 = 0.0048, p = 1.26 × 10-6), followed by excessive somnolence (R2 = 0.0023, p = 7.74 × 10-4) and sleep hyperhidrosis (R2 = 0.0014, p = 9.55 × 10-3). Despite high genetic overlap between MDD and anxiety disorders, PRSs for anxiety disorders correlated with different types of sleep disturbances such as disorders of arousal or nightmares (R2 = 0.0013, p = 0.011). These findings suggest that greater genetic susceptibility to specific psychiatric and neurodevelopmental disorders, as represented by ADHD, MDD, and anxiety disorders, may contribute to greater sleep problems among children.

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

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

Heritability of sleep duration and quality: A systematic review and meta-analysis

Epidemiological and interventional research has highlighted sleep as a potentially modifiable risk factor associated with poor physical and mental health. Emerging evidence from (behavioral) genetic research also shows that sleep characteristics are under strong genetic control. With this study we aimed to meta-analyze the literature in this area to quantify the heritability of sleep duration and sleep quality in the general population. We conducted a systematic literature search in five online databases on January 24th 2020. Two authors independently screened 5644 abstracts, and 160 complete articles for the inclusion criteria of twin studies from the general population reporting heritability statistics on sleep duration and/or quality, and written in English. We ultimately included 23 papers (19 independent samples: 45,328 twins between 6 mo and 88 y) for sleep duration, and 13 papers (10 independent samples: 39,020 twins between 16 and 95 y) for sleep quality. Collectively, we showed that 46% of the variability in sleep duration and 44% of the variability in sleep quality is genetically determined. The remaining variation in the sleep characteristics can mostly be attributed to the unique environment the twins experience, although the shared environment seemed to play a role for the variability of childhood sleep duration. Meta-analyzed heritability estimates for sleep duration, however, varied substantially with age (17% infancy, 20-52% childhood, 69% adolescence and 42-45% adulthood) and reporter (8% parent-report, 38-52% self-report). Heritability estimates for actigraphic and Polysomnography (PSG)-estimated sleep were based on few small samples, warranting more research. Our findings highlight the importance of considering genetic influences when aiming to understand the underlying mechanisms contributing to the trajectories of sleep patterns across the lifespan.

The heritability of insomnia: Systematic review and meta-analysis of twin studies

Twin studies have consistently found that genetic factors explain a substantial proportion of the variance for insomnia. However, studies vary widely in their heritability estimates. Therefore, this meta-analysis aimed to: 1) Estimate the mean heritability of insomnia; 2) Assess heterogeneity among twin studies of insomnia; and 3) Search and analyse characteristics of the studies (moderator variables) that may explain heterogeneity among estimates. For this purpose, separate meta-analyses were carried out for MZ and DZ correlations and for heritability estimates by assuming random-effects models. Thirteen independent samples were included in this meta-analysis. The heterogeneity index for heritability estimates was significant in both best fitting models (I² = 98.77, P < .0001) and full models (I² = 97.80, P < .0001). MZ correlations were higher (0.37; 95%CI: 0.31,.43) than DZ correlations (0.15; 95%CI: 0.12,.18). A mean heritability of 0.39 (95%CI: 0.32,.44) was found for insomnia. These results highlight the role of genetic factors in explaining differences among the population on insomnia and Emphasize heterogeneity among studies. Further research is needed to identify variables that could explain this heterogeneity.

The heritability of insomnia: A meta-analysis of twin studies

Twin studies of insomnia exhibit heterogeneity in estimates of heritability. This heterogeneity is likely because of sex differences, age of the sample, the reporter and the definition of insomnia. The aim of the present study was to systematically search the literature for twin studies investigating insomnia disorder and insomnia symptoms and to meta-analyse the estimates of heritability derived from these studies to generate an overall estimate of heritability. We further examined whether heritability was moderated by sex, age, reporter and insomnia symptom. A systematic literature search of five online databases was completed on 24 January 2020. Two authors independently screened 5644 abstracts, and 160 complete papers for the inclusion criteria of twin studies from the general population reporting heritability statistics on insomnia or insomnia symptoms, written in English, reporting data from independent studies. We ultimately included 12 papers in the meta-analysis. The meta-analysis focussed on twin intra-class correlations for monozygotic and dizygotic twins. Based on these intra-class correlations, the meta-analytic estimate of heritability was estimated at 40%. Moderator analyses showed stronger heritability in females than males; and for parent-reported insomnia symptoms compared with self-reported insomnia symptoms. There were no other significant moderator effects, although this is likely because of the small number of studies that were comparable across levels of the moderators. Our meta-analysis provides a robust estimate of the heritability of insomnia, which can inform future research aiming to uncover molecular genetic factors involved in insomnia vulnerability.

Sleep and schizophrenia: From epiphenomenon to treatable causal target

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

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

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

Sleep disturbance and psychiatric disorders

Signs of mental ill health that cut across psychiatric diagnostic categories at high rates are typically viewed as non-specific occurrences, downgraded in importance and disregarded. However, problems not associated with particular diagnoses should be expected if there is shared causation across mental health conditions. If dynamic networks of interacting symptoms are the reality of mental health presentations, then particularly disruptive and highly connected problems should be especially common. The non-specific occurrence might be highly consequential. One non-specific occurrence that is often overlooked is patients' chronic difficulty in getting good sleep. In this Review, we consider whether disrupted sleep might be a contributory causal factor in the occurrence of major types of mental health disorders. It is argued that insomnia and other mental health conditions not only share common causes but also show a bidirectional relationship, with typically the strongest pathway being disrupted sleep as a causal factor in the occurrence of other psychiatric problems. Treating insomnia lessens other mental health problems. Intervening on sleep at an early stage might be a preventive strategy for the onset of clinical disorders. Our recommendations are that insomnia is assessed routinely in the occurrence of mental health disorders; that sleep disturbance is treated in services as a problem in its own right, yet also recognised as a pathway to reduce other mental health difficulties; and that access to evidence-based treatment for sleep difficulties is expanded in mental health services.

Terminology and assessment tools of psychosis: A systematic narrative review

AIM

Phenomena within the psychosis continuum that varies in frequency/duration/intensity have been increasingly identified. Different terms describe these phenomena, however there is no standardization within the terminology. This review evaluated the definitions and assessment tools of seven terms - (i) 'psychotic experiences'; (ii) 'psychotic-like experiences'; (iii) 'psychotic-like symptoms'; (iv) 'attenuated psychotic symptoms'; (v) 'prodromal psychotic symptoms'; (vi) 'psychotic symptomatology'; and (vii) 'psychotic symptoms'.

METHODS

EMBASE, MEDLINE, and CINAHL were searched during February-March 2019. Inclusion criteria included 1989-2019, full text, human, and English. Papers with no explicit definition or assessment tool, duplicates, conference abstracts, systematic reviews, meta-analyses, or no access were excluded.

RESULTS

A total of 2238 papers were identified and of these, 627 were included. Definitions and assessment tools varied, but some trends were found. Psychotic experiences and psychotic-like experiences were transient and mild, found in the general population and those at-risk. Psychotic-like symptoms were subthreshold and among at-risk populations and non-psychotic mental disorders. Attenuated psychotic symptoms were subthreshold but associated with distress, risk, and help-seeking. Prodromal psychotic symptoms referred to the prodrome of psychotic disorders. Psychotic symptomatology included delusions and hallucinations within psychotic disorders. Psychotic symptoms was the broadest term, encompassing a range of populations but most commonly involving hallucinations, delusions, thought disorder, and disorganization.

DISCUSSION

A model for conceptualizing the required terms is proposed and future directions needed to advance this field of research are discussed.

Maladaptive Personality Traits and 10-Year Course of Psychiatric and Medical Symptoms and Functional Impairment Following Trauma

Background

Personality is a major predictor of many mental and physical disorders, but its contributions to illness course are understudied.

Purpose

The current study aimed to explore whether personality is associated with a course of psychiatric and medical illness over 10 years following trauma.

Methods

World Trade Center (WTC) responders (N = 532) completed the personality inventory for DSM-5, which measures both broad domains and narrow facets. Responders' mental and physical health was assessed in the decade following the WTC disaster during annual monitoring visits at a WTC Health Program clinic. Multilevel modeling was used in an exploratory manner to chart the course of health and functioning, and examine associations of maladaptive personality domains and facets with intercepts (initial illness) and slopes (course) of illness trajectories.

Results

Three maladaptive personality domains-negative affectivity, detachment and psychoticism-were uniquely associated with initial posttraumatic stress disorder (PTSD); detachment and psychoticism were also associated with initial functional impairment. Five facets-emotional lability, anhedonia, callousness, distractibility and perceptual dysregulation-were uniquely associated with initial mental and physical health and functional impairment. Anxiousness and depressivity facets were associated with worse initial levels of psychiatric outcomes only. With regard to illness trajectory, callousness and perceptual dysregulation were associated with the increase in PTSD symptoms. Anxiousness was associated with greater persistence of respiratory symptoms.

Conclusions

Several personality domains and facets were associated with initial levels and long-term course of illness and functional impairment in a traumatized population. Results inform the role of maladaptive personality in the development and maintenance of chronic mental-physical comorbidity. Personality might constitute a transdiagnostic prognostic and treatment target.

Sleep quality, insomnia, and internalizing difficulties in adolescents: insights from a twin study

Study Objectives

There is a well-established association between poor sleep quality and internalizing traits. This relationship has previously been studied using a twin design. However, when it comes to adolescence, there is a paucity of twin studies that have investigated this relationship, despite the importance of this developmental stage for both the development of poor sleep quality and internalizing symptoms. Additionally, anxiety sensitivity, which is commonly associated with poor sleep quality, has not been studied in this context. Our objective was to estimate genetic and environmental influences on the relationships between insomnia, poor sleep quality, and internalizing symptoms in adolescence.

Methods

Insomnia, poor sleep quality, depression, anxiety, and anxiety sensitivity traits were measured in a sample of 5111 twin pairs from the Twins Early Development Study, born between 1994 and 1996 (mean age 16.32 years [SD = 0.68]).

Results

A moderate proportion of the variance for the different variables (.29–.42) was explained by genetic factors. Associations between sleep and internalizing variables were moderate (r = .34–.46) and there was a large genetic overlap between these variables (rA= .51–.73).

Conclusion

This study adds novel information by showing that there are large genetic correlations between sleep disturbances and internalizing symptoms in adolescence.

Schizophrenia liability shares common molecular genetic risk factors with sleep duration and nightmares in childhood

Background: Sleep abnormalities are common in schizophrenia, often appearing before psychosis onset; however, the mechanisms behind this are uncertain. We investigated whether genetic risk for schizophrenia is associated with sleep phenotypes. Methods: We used data from 6,058 children and 2,302 mothers from the Avon Longitudinal Study of Parents and Children (ALSPAC). We examined associations between a polygenic risk score for schizophrenia and sleep duration in both children and mothers, and nightmares in children, along with genetic covariances between these traits. Results: Polygenic risk for schizophrenia was associated with increased risk of nightmares (OR=1.07, 95% CI: 1.01, 1.14, p=0.02) in children, and also with less sleep (β=-44.52, 95% CI: -88.98, -0.07; p=0.05). We observed a similar relationship with sleep duration in mothers, although evidence was much weaker (p=0.38). Finally, we found evidence of genetic covariance between schizophrenia risk and reduced sleep duration in children and mothers, and between schizophrenia risk and nightmares in children. Conclusions: These molecular genetic results support recent findings from twin analysis that show genetic overlap between sleep disturbances and psychotic-like experiences. They also show, to our knowledge for the first time, a genetic correlation between schizophrenia liability and risk of nightmares in childhood.

During day and night: Childhood psychotic experiences and objective and subjective sleep problems

BACKGROUND

Psychotic experiences comprise auditory and visual perceptive phenomena, such as hearing or seeing things that are not there, in the absence of a psychotic disorder. Psychotic experiences commonly occur in the general pediatric population. Although the majority of psychotic experiences are transient, they are predictive of future psychotic and non-psychotic disorders. They have been associated with sleep problems, but studies with objective sleep measures are lacking. This study assessed whether psychotic experiences were associated with actigraphic sleep measures, symptoms of dyssomnia, nightmares, or other parasomnias.

METHODS

This cross-sectional population-based study comprises 4149 children from the Generation R Study. At age 10 years, psychotic experiences including hallucinatory phenomena were assessed by self-report; dyssomnia and parasomnia symptoms were assessed by mother- and child-report. Additionally, at age 11 years, objective sleep parameters were measured using a tri-axial wrist accelerometer in N = 814 children, who wore the accelerometer for five consecutive school days.

RESULTS

Psychotic experiences were not associated with objective sleep duration, sleep efficiency, arousal, or social jetlag. However, psychotic experiences were associated with self-reported dyssomnia (B = 2.45, 95%CI: 2.13-2.77, p < 0.001) and mother-reported parasomnia, specifically nightmares (OR_adjusted = 3.59, 95%CI 2.66-4.83, p < 0.001). Similar results were found when analyses were restricted to hallucinatory phenomena.

CONCLUSIONS

Childhood psychotic experiences were not associated with objective sleep measures. In contrast, psychotic experiences were associated with nightmares, which are a known risk indicator of psychopathology in pre-adolescence. More research is needed to shed light on the potential etiologic or diagnostic role of nightmares in the development of psychotic phenomena.

A Twin Study on the Association Between Psychotic Experiences and Tobacco Use During Adolescence

OBJECTIVE

Psychotic experiences (PE) are dimensional phenomena in the general population that resemble psychotic symptoms, such as paranoia and hallucinations. This is the first twin study to explore the degree to which tobacco use and PE share genetic or environmental influences. Previous studies on the association between adolescent tobacco use and PE have not considered PE dimensionally, included negative symptoms, or accounted for confounding by sleep disturbance and stressful life events.

METHOD

An unselected adolescent twin sample (N = 3,787 pairs; mean age = 16.16 years) reported on PE (paranoia, hallucinations, cognitive disorganization, grandiosity, and anhedonia) and regularity of tobacco use. Parents rated the twins' negative symptoms. Regression analyses were conducted while adjusted for sociodemographic characteristics, prenatal maternal smoking, cannabis use, sleep disturbance, and stressful life events. Bivariate twin modeling was used to estimate the degree of genetic and common and unique environmental influences shared between tobacco use and PE.

RESULTS

Regular smokers were significantly more likely to experience paranoia, hallucinations, cognitive disorganization, and negative symptoms (β = 0.17-0.34), but not grandiosity or anhedonia, than nonsmokers, after adjustment for confounders. Paranoia, hallucinations, and cognitive disorganization correlated ≥0.15 with tobacco use (r = 0.15-0.21, all p < .001). Significant genetic correlations (r_A=0.37-0.45) were found. Genetic influences accounted for most of the association between tobacco use and paranoia (84%) and cognitive disorganization (81%). Familial influences accounted for 80% of the association between tobacco use and hallucinations.

CONCLUSION

Tobacco use and PE during adolescence were associated after adjustment for confounders. They appear to co-occur largely because of shared genetic influences.

Schizophrenia liability shares common molecular genetic risk factors with sleep duration and nightmares in childhood

Background: Sleep abnormalities are common in schizophrenia, often appearing before psychosis onset; however, the mechanisms behind this are uncertain. We investigated whether genetic risk for schizophrenia is associated with sleep phenotypes. Methods: We used data from 6,058 children and 2,302 mothers from the Avon Longitudinal Study of Parents and Children (ALSPAC). We examined associations between a polygenic risk score for schizophrenia and sleep duration in both children and mothers, and nightmares in children, along with genetic covariances between these traits. Results: Polygenic risk for schizophrenia was associated with increased risk of nightmares (OR=1.07, 95% CI: 1.01, 1.14, p=0.02) in children, and also with less sleep (β=-44.52, 95% CI: -88.98, -0.07; p=0.05). We observed a similar relationship with sleep duration in mothers, although evidence was much weaker (p=0.38). Finally, we found evidence of genetic covariance between schizophrenia risk and reduced sleep duration in children and mothers, and between schizophrenia risk and nightmares in children. Conclusions: These molecular genetic results support recent findings from twin analysis that show genetic overlap between sleep disturbances and psychotic-like experiences. They also show, to our knowledge for the first time, a genetic correlation between schizophrenia liability and risk of nightmares in childhood.

Relationship between Sleep and Psychosis in the Pediatric Population: A Brief Review

Sleep disorders are common in several psychiatric disorders, including schizophrenia. In the pediatric population, the relationship between sleep and psychosis is not completely understood due to limited research studies investigating the link. Insomnia is noted to be a predictor of psychosis, especially in ultrahigh risk adolescents. Sleep difficulties are also associated with a two to three-fold increase in paranoid thinking. Biological factors, such as decrease in thalamic volume, have been observed in children with schizophrenia and ultrahigh risk adolescents with associated sleep impairment. Objective studies have indicated possible actigraphy base measures to be the predictor of psychosis after a one year follow-up. The studies using polysomnography have rare and inconsistent results. In this brief review, we provide an overview of existing literature. We also posit that future research will be beneficial in understanding the initiation, course and progression of sleep disturbance in the high risk pediatric population with the goal of implementing interventions to alter the development of psychosis.

Association between sleep, childhood trauma and psychosis-like experiences

Psychosis-like experiences (PLEs), or attenuated positive symptoms of psychosis, present along a severity continuum and have been associated with distressing thoughts and impairments in functioning. Although knowledge of the clinical importance of PLEs is expanding, risk factors for their expression are still poorly understood. Sleep disturbances are one known factor that exacerbate PLEs expression and distress, and trauma exposure is associated with occurrence of PLEs, as well as increased risk of later sleep difficulties. This study examined the joint influences of sleep and trauma on PLEs in an undergraduate sample. Self-report questionnaires on presence and distress of PLEs, sleep problems, and occurrence of previous traumatic experiences were completed by participants (N=409). In order to determine the unique impact of sleep on PLEs, three sets of predictors: sociodemographic, psychosocial (including trauma), and sleep were entered in steps into a hierarchical multiple regression model. In the final model, specific sleep domains uniquely predicted PLEs, while previous trauma exposure, which was a significant predictor when entered in step two with other psychosocial variables, was no longer a significant predictor. Results suggest the possibility that disruptions in sleep following or occurring alongside a traumatic experience may somehow contribute to, or exacerbate the presence of PLEs.

Severe Sleep Deprivation Causes Hallucinations and a Gradual Progression Toward Psychosis With Increasing Time Awake

Background: Going without sleep for long periods of time can produce a range of experiences, including perceptual distortions and hallucinations. Many questions, however, remain unanswered regarding the types of symptoms which are most reliably elicited, the time of symptom onset, and whether symptoms worsen over time toward psychotic decompensation. Since sleep deprivation exceeding 48 h is considered unethical today, an examination of historical studies with extreme sleep-loss duration is needed to obtain information about what happens during prolonged sleep loss. Methods: A systematic-review approach was used to identify experimental and observational studies of sleep deprivation in healthy people which describe the effects of prolonged sleep loss on psychopathological symptoms, without any date restriction. Results: A total of 476 articles were identified. Of these, 21 were eligible for inclusion. Duration of sleep loss ranged between 24 h and 11 nights (total 760 participants; average 72-92 h without sleep). All studies except one reported perceptual changes, including visual distortions (i.e., metamorphopsias), illusions, somatosensory changes and, in some cases, frank hallucinations. The visual modality was the most consistently affected (in 90% of the studies), followed by the somatosensory (52%) and auditory (33%) modalities. Symptoms rapidly developed after one night without sleep, progressing in an almost fixed time-dependent way. Perceptual distortions, anxiety, irritability, depersonalization, and temporal disorientation started within 24-48 h of sleep loss, followed by complex hallucinations and disordered thinking after 48-90 h, and delusions after 72 h, after which time the clinical picture resembled that of acute psychosis or toxic delirium. By the third day without sleep, hallucinations in all three sensory modalities were reported. A period of normal sleep served to resolve psychotic symptoms in many-although not all-cases. Conclusions: Psychotic symptoms develop with increasing time awake, from simple visual/somatosensory misperceptions to hallucinations and delusions, ending in a condition resembling acute psychosis. These experiences are likely to resolve after a period of sleep, although more information is required to identify factors which can contribute to the prevention of persistent symptoms.

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.

Unusual sleep experiences and dissociation as mediators between sleep quality and proneness to hallucinations in a nonclinical population sample: a preliminary study

INTRODUCTION

The purpose of this study was to examine the relationship of sleep quality to proneness to hallucinations and the mediating role of dissociation and unusual sleep experiences in a nonclinical sample.

METHODS

One hundred and seventy-seven participants completed a questionnaire on sleep quality, a dissociative experiences scale, an unusual sleep experiences scale and a hallucination proneness scale.

RESULTS

The results showed a significant positive association between quality of sleep and hallucination proneness, dissociation and unusual sleep experiences, and that dissociation and unusual sleep experiences fully mediated between sleep quality and hallucination proneness.

CONCLUSIONS

Our study highlights the importance of variables related to sleep quality and unusual sleep experiences and dissociation in understanding hallucinations, and the importance of taking these variables into consideration in designing intervention directed at reducing distress caused by hallucinations.

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.

The Experience of Sleep Problems and Their Treatment in Young People at Ultra-High Risk of Psychosis: A Thematic Analysis

We view sleep disruption as a contributory causal factor in the development of psychotic experiences. Clinical trials indicate that psychological interventions targeting insomnia result in improvements in both sleep and psychotic experiences. The aim of this study was to gain the perspective of young people at ultra-high risk of psychosis on their sleep problems and associated psychological treatment. Interviews were conducted with 11 patients, aged 15-22 years, at ultra-high risk of psychosis who had received a psychological sleep intervention. Responses were analyzed using thematic analysis. Disrupted sleep timing and a lack of routine were the characteristic hallmarks of participants' sleep problems. Sleep disturbance, psychological wellbeing, and functioning had a reciprocal relationship. There were negative expectations prior to therapy, however meaningful improvements occurred in sleep, mood, and functioning. The active implementation of therapy techniques was highlighted as important. These findings indicate that the treatment of sleep problems is highly valued and has a meaningful impact on wellbeing in young people at ultra-high risk of psychosis.

Sleep Treatment Outcome Predictors (STOP) Pilot Study: a protocol for a randomised controlled trial examining predictors of change of insomnia symptoms and associated traits following cognitive-behavioural therapy for insomnia in an unselected sample

INTRODUCTION

Cognitive-behavioural therapy for insomnia (CBT-I) leads to insomnia symptom improvements in a substantial proportion of patients. However, not everyone responds well to this treatment, and it is unclear what determines individual differences in response. The broader aim of this work is to examine to what extent response to CBT-I is due to genetic and environmental factors. The purpose of this pilot study is to examine feasibility of a design to test hypotheses focusing on an unselected sample, that is, without selection on insomnia complaints, in order to plan a larger behavioural genetics study where most participants will likely not have an insomnia disorder.

METHODS AND ANALYSIS

A two parallel-group randomised controlled trial is being conducted across three London universities. Female students (minimum age 18 years) enrolled on a psychology programme at one of the three sites were invited to participate. The target number of participants to be recruited is 240. Following baseline assessments, participants were randomly allocated to either the treatment group, where they received weekly sessions of digital CBT-I for 6 weeks, or the control group, where they completed an online puzzle each week for 6 weeks. Follow-up assessments have taken place mid-intervention (3 weeks) and end of intervention (6 weeks). A 6-month follow-up assessment will also occur. Primary outcomes will be assessed using descriptive statistics and effect size estimates for intervention effects. Secondary outcomes will be analysed using multivariate generalised estimating equation models.

ETHICS AND DISSEMINATION

The study received ethical approval from the Research Ethics and Integrity subcommittee, Goldsmiths, University of London (application reference: EA 1305). DNA sample collection for the BioResource received ethical approval from the NRES Committee South Central-Oxford (reference number: 15/SC/0388). The results of this work shall be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03062891; Results.

Cognitive, affective, and social factors maintaining paranoia in adolescents with mental health problems: A longitudinal study

Paranoia may be a significant concern during adolescence, but there has been little research on excessive mistrust in young people. In this longitudinal study we set out to test the predictive ability of a number of cognitive, affective, and social factors in the early development of paranoia in a clinical adolescent population. Thirty four help-seeking adolescents, aged 11-16 years, reporting paranoid thoughts and attending mental health services were recruited. Self-report and interview assessments of paranoia were conducted at baseline. Measures relating to a cognitive model of persecutory delusions were completed. Paranoia was reassessed after three months with thirty three participants. Significant predictors of paranoia persistence were anxiety, depression, worry, negative self-beliefs, perceptual anomalies, insomnia, affective reactivity, bullying, and cyber victimization. No effect was found for reasoning bias or negative perceptions of academic ability, social competence, and physical appearance. In conclusion, many of the maintenance factors implicated in adult paranoia are likely to prove important in the early development of paranoia in young people. Further experimental and treatment studies are now needed to examine the causal role of these factors in the occurrence of paranoia in adolescents.

The effects of improving sleep on mental health (OASIS): a randomised controlled trial with mediation analysis

BACKGROUND

Sleep difficulties might be a contributory causal factor in the occurrence of mental health problems. If this is true, improving sleep should benefit psychological health. We aimed to determine whether treating insomnia leads to a reduction in paranoia and hallucinations.

METHODS

We did this single-blind, randomised controlled trial (OASIS) at 26 UK universities. University students with insomnia were randomly assigned (1:1) with simple randomisation to receive digital cognitive behavioural therapy (CBT) for insomnia or usual care, and the research team were masked to the treatment. Online assessments took place at weeks 0, 3, 10 (end of therapy), and 22. The primary outcome measures were for insomnia, paranoia, and hallucinatory experiences. We did intention-to-treat analyses. The trial is registered with the ISRCTN registry, number ISRCTN61272251.

FINDINGS

Between March 5, 2015, and Feb 17, 2016, we randomly assigned 3755 participants to receive digital CBT for insomnia (n=1891) or usual practice (n=1864). Compared with usual practice, the sleep intervention at 10 weeks reduced insomnia (adjusted difference 4·78, 95% CI 4·29 to 5·26, Cohen's d=1·11; p<0·0001), paranoia (-2·22, -2·98 to -1·45, Cohen's d=0·19; p<0·0001), and hallucinations (-1·58, -1·98 to -1·18, Cohen's d=0·24; p<0·0001). Insomnia was a mediator of change in paranoia and hallucinations. No adverse events were reported.

INTERPRETATION

To our knowledge, this is the largest randomised controlled trial of a psychological intervention for a mental health problem. It provides strong evidence that insomnia is a causal factor in the occurrence of psychotic experiences and other mental health problems. Whether the results generalise beyond a student population requires testing. The treatment of disrupted sleep might require a higher priority in mental health provision.

FUNDING

Wellcome Trust.

Do depressive symptoms predict paranoia or vice versa?

BACKGROUND AND OBJECTIVES

Affective versus nonaffective psychoses are today no longer regarded as mutually exclusive disorders. Theorists have recently highlighted the role of affective symptoms in the formation of paranoid beliefs, particularly negative beliefs about the self, interpersonal sensitivity, sleep disturbances, and worrying, which exist along a continuum in the general population. For the present study, we tested the bidirectional causal relationships between paranoia and affect.

METHOD

A large population sample (N = 2,357) was examined at three time-points (baseline, six months, two years) as to the severity of subclinical paranoid beliefs (Paranoia Checklist, PCL) and depressive symptoms (Patient Health Questionnaire-9, PHQ-9). Worrying and avoidance were measured with items from the Maladaptive and Adaptive Coping Style Questionnaire (MAX).

RESULTS

Depression and paranoid symptoms were strongly cross-sectionally related (r = 0.69) and showed high stability (r > 0.72). Depressive symptoms at T2 predicted paranoid symptoms at T3 (beta = 0.16; no significant relationship from T1 to T2), whereas paranoid symptoms predicted depressive symptoms from T1 to T2 (beta = 0.09; no significant relationship from T2 to T3).

LIMITATIONS

Results should be replicated in a sample of paranoid patients, as risk factors for subclinical versus manifest paranoia may differ. Some constructs were measured with single items derived from a new scale.

CONCLUSIONS

The predictive association of depression to subsequent paranoia was small and confined to the long interval from T2 to T3. Treatments should target both paranoia and depression - irrespective of their causal relationship - particularly as patients with psychosis consider treatment of their emotional problems a priority.

Sleep disturbances in individuals at clinical high risk for psychosis

There has been recent interest in understanding the role that sleep disturbance plays in patients at Clinical High Risk for psychosis (CHR). We assessed sleep disturbance in 194 CHR patients and 66 healthy control subjects and their relationship to symptoms (positive, negative and general functioning). Patients experienced significantly more sleep disturbance than healthy control subjects and their sleep disturbance was related to greater positive and negative symptoms and worse overall functioning. Targeting sleep disturbance in CHR individuals may provide alternative means of treating the CHR syndrome.

ADHD and Sleep Quality: Longitudinal Analyses From Childhood to Early Adulthood in a Twin Cohort

Attention-deficit/hyperactivity disorder (ADHD) is associated with poor sleep quality, but there is more to learn about the longitudinal association and aetiology of this association. We investigated the following: (a) Is there an association between childhood ADHD and poor sleep quality in young adulthood? (b) Is this driven by the long-term effects of childhood ADHD or concurrent associations with ADHD in young adulthood? (c) To what extent do genetic and environmental influences explain the overlap between symptoms of ADHD and poor sleep quality? Participants were from the Environmental Risk Longitudinal Twin Study of 2,232 twin children born in the United Kingdom in 1994-1995. We ascertained ADHD diagnoses at ages 5, 7, 10, 12, and 18. We assessed sleep quality using the Pittsburgh Sleep Quality Index at age 18. We used regression models to examine longitudinal associations and bivariate twin modelling to test genetic and environmental influences. Children with ADHD had poorer sleep quality in young adulthood, but only if their ADHD persisted. Adults with ADHD had more sleep problems than those without ADHD, over and above psychiatric comorbidity and maternal insomnia. ADHD and sleep problems in young adulthood were associated because of genetic (55%) and nonshared environmental influences (45%). Should ADHD remit, children with ADHD do not appear to have an increased risk of later sleep problems. Good quality sleep is important for multiple areas of functioning, and a better understanding of why adults with ADHD have poorer sleep quality will further the goal of improving treatments.