Sleep disturbance, personality and the onset of depression and anxiety: prospective cohort study

Risk of obstructive sleep apnea and excessive daytime sleepiness in hospitalized psychiatric patients

OBJECTIVES

This study evaluated the risk of developing obstructive sleep apnea (OSA) and excessive daytime sleepiness (EDS) in hospitalized psychiatric patients at the American University of Beirut Medical Center (AUB-MC). Factors associated with OSA and EDS occurrence in this sample were also examined.

METHODS

The Berlin questionnaire and the Epworth sleepiness scale; which respectively evaluate OSA and EDS symptoms, were administered to individuals hospitalized at an acute psychiatric treatment unit at the AUB-MC between the dates of January 2014 and October 2016. Additional data collected included general demographics, psychiatric diagnoses, and questionnaires evaluating depression and anxiety symptoms. Statistical analyses utilizing SPSS were performed to determine the prevalence of OSA and EDS, as well as their respective associations with patient profiles.

RESULTS

Our results showed that 39.5% of participants were found to have a high risk of sleep apnea and 9.9% of the participants were found to have abnormal daytime sleepiness. The risk of developing OSA was associated with a higher body mass index (BMI) (P=0.02), and depression severity (patient health questionnaire 9 score) (P=0.01). Increasing severity of depressive symptoms was associated with a higher risk of sleep apnea (P=0.01). BMI (odds ratio [OR] =5.97, 95% confidence interval [CI] 1.89-18.82) and depression severity (OR =4.04, 95% CI 1.80-9.07) were also found to be predictors of OSA. The psychiatric diagnoses of the participants were not found to have a significant association with the risk of sleep apnea.

CONCLUSION

The risk of OSA is increased among hospitalized psychiatric patients, and this condition can have detrimental effects on psychiatric patients. OSA appears to be under-recognized in this population, psychiatrists should screen for OSA in hospitalized psychiatric patients and refer them for diagnostic testing or treatment when indicated.

Associations of Perceived Stress, Resilience and Social Support with Sleep Disturbance Among Community-dwelling Adults

Sleep disturbance is often described as sleeping poorly, difficulty falling asleep and maintaining sleep, and waking early. Currently, most studies examining sleep disturbance have focused on negative psychological variables; however, few studies have combined both negative and positive psychosocial factors to assess sleep. The aim of this study was to investigate the prevalence of sleep disturbance and psychosocial correlates in Chinese community-dwelling adults. A total of 1471 adults, between 18 and 60 years old, from eight selected community settings in Jinan, China, were surveyed using the Pittsburgh Sleep Quality Index, Perceived Stress Scale, 10-item Connor-Davidson Resilience Scale and Multidimensional Scale of Perceived Social Support and provided sociodemographic information. We found that the prevalence of sleep disturbance was 33.9%. After adjusting for age, employment status and physical co-morbidity, perceived stress was significantly associated with sleep disturbance [odds ratio (OR) = 1.14, p < 0.001], while resilience and social support were associated with a low likelihood of sleep disturbance (OR = 0.90, p < 0.001; OR = 0.97, p < 0.001). Furthermore, regression analysis showed that the interaction between perceived stress and resilience was significant (p < 0.05). Resilience buffered the negative impact of perceived stress on sleep disturbance. Given the close relationship between sleep disturbance and psychosocial correlates, the development of effective intervention programmes to improve sleep quality in this population should be considered. Copyright © 2015 John Wiley & Sons, Ltd.

The role of rumination in illness trajectories in youth: linking trans-diagnostic processes with clinical staging models

Research in developmental psychopathology and clinical staging models has increasingly sought to identify trans-diagnostic biomarkers or neurocognitive deficits that may play a role in the onset and trajectory of mental disorders and could represent modifiable treatment targets. Less attention has been directed at the potential role of cognitive-emotional regulation processes such as ruminative response style. Maladaptive rumination (toxic brooding) is a known mediator of the association between gender and internalizing disorders in adolescents and is increased in individuals with a history of early adversity. Furthermore, rumination shows moderate levels of genetic heritability and is linked to abnormalities in neural networks associated with emotional regulation and executive functioning. This review explores the potential role of rumination in exacerbating the symptoms of alcohol and substance misuse, and bipolar and psychotic disorders during the peak age range for illness onset. Evidence shows that rumination not only amplifies levels of distress and suicidal ideation, but also extends physiological responses to stress, which may partly explain the high prevalence of physical and mental co-morbidity in youth presenting to mental health services. In summary, the normative developmental trajectory of rumination and its role in the evolution of mental disorders and physical illness demonstrates that rumination presents a detectable, modifiable trans-diagnostic risk factor in youth.

Effectiveness of an online insomnia program (SHUTi) for prevention of depressive episodes (the GoodNight Study): a randomised controlled trial

BACKGROUND

In view of the high co-occurrence of depression and insomnia, a novel way to reduce the risk of escalating depression might be to offer an insomnia intervention. We aimed to assess whether an online self-help insomnia program could reduce depression symptoms.

METHODS

We did this randomised controlled trial at the Australian National University in Canberra, Australia. Internet users (aged 18-64 years) with insomnia and depression symptoms, but who did not meet criteria for major depressive disorder, were randomly assigned (1:1), via computer-generated randomisation, to receive SHUTi, a 6 week, modular, online insomnia program based on cognitive behavioural therapy for insomnia, or HealthWatch, an interactive, attention-matched, internet-based placebo control program. Randomisation was stratified by age and sex. Telephone-based interviewers, statisticians, and chief investigators were masked to group allocation. The primary outcome was depression symptoms at 6 months, as measured with the Patient Health Questionnaire (PHQ-9). The primary analysis was by intention to treat. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12611000121965.

FINDINGS

Between April 30, 2013, and June 9, 2014, we randomly assigned 1149 participants to receive SHUTi (n=574) or HealthWatch (n=575), of whom 581 (51%) participants completed the study program assessments at 6 weeks and 504 (44%) participants completed 6 months' follow-up. SHUTi significantly lowered depression symptoms on the PHQ-9 at 6 weeks and 6 months compared with HealthWatch (F[degrees of freedom 2,640·1]=37·2, p<0·0001). Major depressive disorder was diagnosed in 22 (4%) participants at 6 months (n=9 in the SHUTi group and n=13 in the HealthWatch group), with no superior effect of SHUTi versus HealthWatch (Fisher's exact test=0·52; p=0·32). No adverse events were reported.

INTERPRETATION

Online cognitive behaviour therapy for insomnia treatment is a practical and effective way to reduce depression symptoms and could be capable of reducing depression at the population level by use of a fully automatised system with the potential for wide dissemination.

FUNDING

Australian National Health and Medical Research Council.

Restless leg syndrome in hospitalized psychiatric patients in Lebanon: a pilot study

OBJECTIVES

To characterize and describe the prevalence of restless leg syndrome (RLS) in hospitalized psychiatric patients and to investigate the correlations between patient profile and RLS.

METHODS

Demographic information, psychiatric diagnoses, psychotropic medication use, and history of substance use were collected from hospitalized psychiatric patients at the American University of Beirut Medical Center; Beirut, Lebanon. A validated questionnaire to evaluate RLS symptomatology was also administered to 126 participants who agreed to participate, as well as questionnaires for insomnia, depression, and anxiety symptoms. Statistical analysis was conducted to detect the prevalence of RLS among the participants and to examine correlations with RLS in a hospitalized psychiatric population.

RESULTS

Out of the 126 participants who completed the survey, RLS was detected in 18% of the participants. Of interest, RLS was also found to be associated with higher depressive symptomatology, suicidal ideation, and working night shifts.

A systematic review of sleep disturbance in anxiety and related disorders

Recent research suggests that sleep disturbance may be a transdiagnostic process, and there is increasing interest in examining how sleep disturbance may contribute to anxiety and related disorders. The current review summarizes and synthesizes the extant research assessing sleep in anxiety and related disorders. The findings suggest that sleep disturbance exacerbates symptom severity in the majority of anxiety and related disorders. However, the nature of sleep disturbance often varies as a function of objective versus subjective assessment. Although sleep disturbance is a correlate of most anxiety and related disorders, a causal role for sleep disturbance is less clear. A model of potential mechanisms by which sleep disturbance may confer risk for the development of anxiety and related disorders is discussed. Future research integrating findings from basic sleep research with current knowledge of anxiety and related disorders may facilitate the development of novel treatments for comorbid sleep disturbance and clinical anxiety.

Bidirectional relationship between sleep and optimism with depressive mood as a mediator: A longitudinal study of Chinese working adults

OBJECTIVE

Sleep and optimism are important psycho-biological and personality constructs, respectively. However, very little work has examined the causal relationship between them, and none has examined the potential mechanisms operating in the relationship. This study aimed to understand whether sleep quality was a cause or an effect of optimism, and whether depressive mood could explain the relationship.

METHOD

Internet survey data were collected from 987 Chinese working adults (63.4% female, 92.4% full-time workers, 27.0% married, 90.2% Hong Kong residents, mean age=32.59 at three time-points, spanning about 19 months). Measures included a Chinese attributional style questionnaire, the Pittsburgh Sleep Quality Index, and the Depression Anxiety Stress Scale.

RESULTS

Cross-sectional analyses revealed moderate correlations among sleep quality, depressive mood, and optimism. Cross-lagged analyses showed a bidirectional causality between optimism and sleep. Path analysis demonstrated that depressive mood fully mediated the influence of optimism on sleep quality, and it partially mediated the influence of sleep quality on optimism.

CONCLUSION

Optimism improves sleep. Poor sleep makes a pessimist. The effects of sleep quality on optimism could not be fully explained by depressive mood, highlighting the unique role of sleep on optimism. Understanding the mechanisms of the feedback loop of sleep quality, mood, and optimism may provide insights for clinical interventions for individuals presented with mood-related problems.

Mood instability as a precursor to depressive illness: A prospective and mediational analysis

OBJECTIVE

Mood instability levels are high in depression, but temporal precedence and potential mechanisms are unknown. Hypotheses tested were as follows: (1) mood instability is associated with depression cross-sectionally, (2) mood instability predicts new onset and maintenance of depression prospectively and (3) the mood instability and depression link are mediated by sleep problems, alcohol abuse and life events.

METHOD

Data from the National Psychiatric Morbidity Survey 2000 at baseline (N = 8580) and 18-month follow-up (N = 2413) were used. Regression modeling controlling for socio-demographic factors, anxiety and hypomanic mood was conducted. Multiple mediational analyses were used to test our conceptual path model.

RESULTS

Mood instability was associated with depression cross-sectionally (odds ratio: 5.28; 95% confidence interval: [3.67, 7.59]; p < 0.001) and predicted depression inception (odds ratio: 2.43; 95% confidence interval: [1.03-5.76]; p = 0.042) after controlling for important confounders. Mood instability did not predict maintenance of depression. Sleep difficulties and severe problems with close friends and family significantly mediated the link between mood instability and new onset depression (23.05% and 6.19% of the link, respectively). Alcohol abuse and divorce were not important mediators in the model.

CONCLUSION

Mood instability is a precursor of a depressive episode, predicting its onset. Difficulties in sleep are a significant part of the pathway. Interventions targeting mood instability and sleep problems have the potential to reduce the risk of depression.

Association between personality traits and DSM-IV diagnosis of insomnia in peri- and postmenopausal women

OBJECTIVE

The aim of this study was to determine the role of personality factors in the development of DSM-IV insomnia coincident with perimenopause.

METHODS

Perimenopausal women (35 women with DSM-IV insomnia and 28 women with self-reported normal sleep) underwent clinical assessments and completed menopause-related questionnaires, the NEO Five Factor Inventory and the Structured Interview for DSM-IV Personality. Logistic regressions determined whether personality factors and hot flash-related interference were associated with an insomnia diagnosis concurrent with the menopausal transition.

RESULTS

Women with insomnia reported higher neuroticism, lower agreeableness, and lower conscientiousness than controls on the NEO Five Factor Inventory. Moreover, women with insomnia were more likely to meet DSM-IV criteria for cluster C personality disorders, particularly obsessive-compulsive personality disorder, on the Structured Interview for DSM-IV Personality. Women with insomnia were more likely to have had a past depressive episode and a history of severe premenstrual symptoms. Findings from regressions revealed that higher neuroticism and greater interference from hot flashes were associated with insomnia classification even after controlling for history of depression, suggesting that sensitivity to hot flashes and a greater degree of neuroticism are independent contributors toward establishing which women are most likely to have sleep problems during perimenopause.

CONCLUSIONS

Findings show the relevance of personality factors, particularly neuroticism and obsessive-compulsive personality, to a woman's experience of insomnia as she goes through the menopausal transition.

Validation of Arabic versions of three sleep surveys

BACKGROUND

Research on sleep health is lacking in developing countries, particularly among the Sudanese population. This contributes to a number of social and safety risks such as workplace injury, daytime sleepiness, automobile accidents, and more. The current study aims to validate three Arabic questionnaires related to sleep health, namely the Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI), and Restless Legs Syndrome (RLS).

METHODS

A random sample of 83 Sudanese participants was surveyed for the purpose of testing the reliability and validity of the Arabic version of the ESS, ISI, and RLS. The present study used exploratory factor analysis (EFA) of item scores to examine a potential single-factor structure of the ESS, ISI, and RLS. Reliability and validity of the instruments were assessed by internal consistency and construct validity, respectively.

RESULTS

The internal consistency within the ESS, ISI, and RLS subscales was high, with Cronbach's alpha of 0.84, 0.87, and 0.94, respectively. EFA results showed the RLS and ISI scales were dominated by a single-factor structure that explained at least 84.2% and 65.70% respectively of the total variance. The ESS required a two-factor solution that explained 64.5% of the total variance, so the single-factor structure does not appear to be a good measure of the Arabic version of the ESS.

CONCLUSION

The Arabic versions of the ESS, ISI, and RLS are valid and reliable tools. The RLS and ISI seem to have better psychometric properties than the ESS.

Predictors of help-seeking for suicidal ideation in the community: risks and opportunities for public suicide prevention campaigns

Help-seeking behaviour for suicidality is low and the reasons for this have not systematically been examined. The aim of the current study was to examine the relationship between suicide stigma, suicide literacy and help-seeking attitudes and intentions. One thousand two hundred seventy-four Australian adults recruited via Facebook completed an online survey assessing a range of mental health outcomes. High suicide literacy and low suicide stigma were significantly associated with more positive help-seeking attitudes and, among a subsample of 534, greater intentions to seek help. Attribution of suicide to isolation was associated with more positive attitudes toward help-seeking and greater intentions to seek help, while respondents experiencing suicidal ideation had more negative attitudes toward help-seeking and lower intentions to seek help. Lower depressive symptoms, older age and female gender were associated with more positive help-seeking attitudes and higher help-seeking intentions. However, there were differential associations of specific suicide knowledge items and specific stigmatising attitudes with help-seeking outcomes; suggesting a nuanced approach may be required to promote help seeking for suicidality. Suicide knowledge and attitudes play an important role in the help-seeking process for suicide and should be carefully considered in the development of public awareness campaigns.

Risk factors for the onset of panic and generalised anxiety disorders in the general adult population: a systematic review of cohort studies

BACKGROUND

We aimed to assess available evidence on risk factors associated with the onset of panic disorder (PD) and/or generalised anxiety disorder (GAD) in cohort studies in the general adult population.

METHODS

Systematic review using MEDLINE, PsycINFO and Embase. Search terms included panic disorder, generalised anxiety disorder, cohort studies and risk factors.

RESULTS

We finally selected 21 studies, involving 163,366 persons with a median follow-up of 5 years. 1) Sociodemographic factors: PD was associated with age, female gender, and few economic resources. GAD was associated with age, non-Hispanics and Blacks, being divorced or widowed, and few economic resources. 2) Psychosocial factors: PD was associated with smoking and alcohol problems. GAD was associated with stressful life events in childhood and adulthood, and personality. 3) Physical and mental health factors: PD was associated with the number of physical diseases suffered and the joint hypermobility syndrome. PD was also associated with a parental history of mental disorders, as well as with other anxiety disorders and other mental health problems in the person affected. GAD was associated with a parental history of mental disorders, as well as with other anxiety disorders and other mental health problems in the person affected, plus already having received psychiatric care.

LIMITATIONS

Few studies examined the same risk factors.

CONCLUSIONS

Sociodemographic, psychosocial and mental-physical health risk factors were determinant for the onset of PD and GAD in the general adult population. These findings could be useful for developing preventive interventions in PD and GAD.

Somatic and cognitive symptoms as indicators of potential endophenotypes in bipolar spectrum disorders: an exploratory and proof-of-concept study comparing bipolar II disorder with recurrent brief depression and healthy controls

BACKGROUND

We examined whether somatic symptoms reported by patients with bipolar spectrum disorder (BSD), in this study defined as bipolar II (BD-2) or recurrent brief depression with (RBD-H) or without (RBD-O) a history of hypomanic symptoms might point to the possible underlying disease markers (endophenotypes). We hypothesized that somatic symptoms that are possible indirect indicators of endophenotypes should be more prevalent among patients than among healthy controls; should not correlate with neuroticism; should not correlate with the severity of current mental status (e.g., anxiety, depression); and should not correlate with the use of psychotropic drugs including antiepileptics or be explained by co-morbid medical diseases.

METHODS

Sixty-one patients (BD-2: n=21; RBD-H: n=19; RBD-O: n=21) were compared with 21 healthy controls. Assessments included a 123-item somatic symptom checklist; assessments for neuroticism, anxiety and depression. Candidate somatic symptoms were selected using a 4-step inclusion/exclusion procedure.

RESULTS

Seven symptoms survived in all three groups: general (fatigue, feeling exhausted); sensory (leaden sensation in legs, pain in the body, impaired sense of smell); cognitive (loss of memory) and autonomic (excessive perspiration). In addition 15 symptoms survived in one or two groups (examples: impaired hearing, hypersensitivity to sound, inability to find words).

LIMITATIONS

Possible selection bias and small sample size precludes firm conclusions with regards to specific symptoms.

CONCLUSION

Our approach identified symptoms for which an association with BSDs has been suggested previously, as well as symptoms not commonly associated with BSDs. The findings support the feasibility and validity of using assessment of somatic symptoms as an approach to identify potential endophenotypes in BSDs.

A seven day actigraphy-based study of rumination and sleep disturbance among young adults with depressive symptoms

OBJECTIVES

Trait ruminators exhibit significantly higher levels of sleep disturbance than those without this cognitive vulnerability. However, support for the sleep disruptive effects of state rumination, especially in the pre-sleep period, is rare, and hindered by methodological drawbacks such as self-report and single night assays of sleep. Finally, despite the pervasiveness of the ruminative response style among individuals with depression, the association between rumination and sleep disturbance has not been explored in this population. The present study employed a week-long daily sampling approach to examine the effects of naturally occurring pre-sleep rumination on self-reported and actigraphy-based sleep among individuals with high depressive symptomatology.

METHODS

Forty-two university students (19.6±3.2 yo;73.8% female), all of whom reported at least moderate levels of depressive symptoms, completed a short questionnaire after waking each morning for seven days. On this questionnaire, they self-reported sleep indices from the previous night and levels of engagement in pre-sleep rumination. Sleep was also monitored throughout this period via wrist actigraphy. Hierarchical-linear-modeling was used to examine the association between nightly rumination and sleep.

RESULTS

Nightly variations in pre-sleep rumination were predictive of significantly longer actigraphy- and diary-based sleep onset latency (SOL). Notably, a 1 SD increase on the pre-sleep rumination scale was associated with an approximately 7 minute increase in actigraphy-based SOL, even after controlling for baseline sleep disturbance and depressive symptoms.

CONCLUSIONS

These data offer compelling evidence for the impact of pre-sleep rumination on sleep onset, providing insight into one potential mechanism that triggers sleep disturbance among individuals with depressive symptoms.

Sleep difficulty mediates effects of vasomotor symptoms on mood in younger breast cancer survivors

OBJECTIVE

Treatment-induced early menopause occurs in > 80% of premenopausal women diagnosed with breast cancer. This study explored the relationship between vasomotor symptoms (VMS), sleep and mood in women aged 40-51 years with non-metastatic breast cancer.

METHODS

Cross-sectional study using validated questionnaires (Greene Climacteric scale and Hospital Anxiety and Depression Scale, HADS). Women (n = 114) were recruited from the community and hospital outpatient clinics. Frequency determination and structural equation modeling (SEMod) were used to examine the relationship between the latent variables: VMS, anxiety, and depression, and the indicator variable: difficulty sleeping.

RESULTS

Participants' mean age was 47 years and 94% became menopausal after breast cancer diagnosis. Difficulty sleeping was reported by 82% of women with 46% reporting (Likert scale) 'quite a bit/extremely'. Most women reported night sweats (77% of women: 47% reporting 'quite a bit/extremely') and hot flushes (84% of women: 50% reporting 'quite a bit/extremely'). HADS scores indicated clinically relevant depression and anxiety in 98% and 99% of women, respectively. SEMod revealed that VMS contributed to difficulty sleeping (standardized coefficient = 0.54; p < 0.001) and difficulty sleeping mediated the relationship between VMS and anxiety (standardized coefficient = 0.34; p = 0.03). However, difficulty sleeping did not have a significant direct impact on depression (standardized coefficient = -0.03; p = 0.8), although anxiety was a strong predictor of depression (standardized coefficient = 0.83; p = 0.015).

CONCLUSIONS

VMS, sleep and mood disturbance are commonly experienced by younger women with breast cancer. Using SEMod, we demonstrate for the first time that VMS may directly influence sleep in these women. VMS may have an indirect effect on mood, partly mediated by sleep difficulty.

Delayed sleep onset in depressed young people

BACKGROUND

The circadian abnormality of delayed sleep phase has been suggested to characterise a subgroup of depressed young adults with different risk factors and course of illness. We aim to assess the prevalence and factors, particularly substance use, associated with such delay in a large help-seeking cohort of young people with mental health problems.

METHODS

From a consecutively recruited sample of 802 help-seeking young people, 305 (38%) had at least moderate depressive symptoms (QIDS-C16 >10), sleep data and did not have a chronic severe mental illness. Demographic and clinical characteristics were evaluated through self report and clinical interview. Delayed sleep phase was defined as a sleep onset between the hours of 02:00 a.m. - 06:00 a.m. and the characteristics of this group were compared to normal phase sleepers.

RESULTS

Delayed sleep onset was reported amongst 18% (n = 56/305) of the depressed group compared to 11% of the non-depressed young people. Amongst the depressed group, delayed sleep onset was associated with tobacco, alcohol and cannabis misuse and short sleep duration (x̅: 5.8 hrs vs. x̅: 7.8 hrs). There were no differences in demographic factors, personality traits or symptoms. Tobacco smoking was very common: In logistic regression analyses only tobacco use (OR 2.28, 95% CI: 1.04 - 5.01) was associated with delayed sleep onset. There was no interaction with age.

CONCLUSIONS

Delayed sleep onset was twice as common in depressed young people as the general population and young people with other mental health problems, and is a potential marker for a subgroup of mood disorders. Those with delayed sleep onset were not more severely depressed but had short sleep duration, a risk for chronic psychological ill health, and higher levels of tobacco use. Nicotine use was common in this group, has biological evidence as a sleep disrupter, and requires specifically addressing in this population.

Maintaining sleep and physical activity alleviate mood instability

OBJECTIVE

Building on previous work indicating that mood instability is the hallmark of neuroticism, our aim was to examine whether changes in exercise, sleep duration and leisure predicted decreases in mood instability with time.

METHODS

We used data from 3374 participants of the British Health and Lifestyle Study who answered the Eysenck Personality Inventory-Neuroticism subscale (EPI-N) and the General Health Questionnaire on two occasions 7 years apart. We predicted mood instability scores derived from the EPI-N at follow-up using self-reported changes in exercise, sleep duration and leisure hours between the two time points as independent variables.

RESULTS

We confirmed the observation that mood instability decreases with age. Maintaining one's exercise at baseline level decreased mood instability (beta=-0.21) while sleeping less increased mood instability (beta=0.14). Change in leisure time was not independently related to mood instability after accounting for the two other lifestyle factors.

CONCLUSION

Personality, at least with regard to mood instability, can be modified by lifestyle factors. Exercise and sleep support mood stability and could be important components of preventative mental health (as well as physical health) benefits.

A Systematic Review Assessing Bidirectionality between Sleep Disturbances, Anxiety, and Depression

STUDY OBJECTIVES

To investigate whether sleep disturbances are bidirectionally related to anxiety and depression, and thus identify potential risk factors for each problem.

DESIGN

A systematic review was conducted on 9 studies (8 longitudinal, 1 retrospective) that assessed bidirectionality between a sleep disturbance, and anxiety or depression. Treatment studies were excluded, along with those solely based on clinical samples or cohorts at high risk of suffering from a sleep disturbance, anxiety and depression. Eligible studies were identified by searching PubMed, PsychINFO, Embase, and Scopus databases, and reference lists of eligible studies. Publication dates ranged from the beginning of each database to December 2011.

MEASUREMENTS AND RESULTS

Syntheses of longitudinal studies suggested insomnia and sleep quality were bidirectionally related to anxiety and depression, and depression/anxiety, respectively. Childhood sleep problems significantly predicted higher levels of depression and a combined depression/anxiety variable, but not vice-versa. A one-way relationship was found where anxiety predicted excessive daytime sleepiness, but excessive daytime sleepiness was not associated with depression.

CONCLUSIONS

Definitive conclusions regarding bidirectionality cannot be made for most sleep disturbances due to the small number and heterogeneity of cohort samples used across studies. Nevertheless, best available evidence suggests insomnia is bidirectionally related to anxiety and depression. Clinical and theoretical implications are discussed.

CITATION

Alvaro PK; Roberts RM; Harris JK. A systematic review assessing bidirectionality between sleep disturbances, anxiety, and depression. SLEEP 2013;36(7):1059-1068.

Effects of personality traits on the manifestations of irritable bowel syndrome

Objective

Previous studies have reported that patients with irritable bowel syndrome (IBS) show high neuroticism. However, the precise association between the IBS subtypes and the degree of neuroticism in younger populations is largely unknown. We tested our hypothesis that subjects with diarrhea-predominant IBS may have a higher degree of neuroticism than subjects without IBS or those with other subtypes of IBS. We also verified the additional hypothesis that the severity of neuroticism might be correlated with the severity of IBS in younger populations.

Methods

We conducted a cross-sectional survey of 557 university students, ranging in age from 18 to 21 years. Presence/ absence of IBS and determination of the IBS subtype was by the Rome II Modular Questionnaire, while the severity of IBS was determined by the IBS severity index (IBS-SI). The degree of neuroticism was evaluated using the Maudsely Personality Inventory (MPI). The presence/absence of psychological distress was measured with the K6 scale.

Results

Neuroticism scores in the subjects with diarrhea-predominant IBS were significantly higher than those in the non-IBS subjects or subjects with constipation-predominant IBS. The neuroticism scores were significantly correlated with the IBS-SI scores in all subjects with IBS.

Conclusion

These results suggest that neuroticism is involved in the pathophysiology of IBS in young subjects, especially in that of the diarrhea-predominant subtype.