REM sleep dysregulation in depression: state of the art

Sleep and optimism: A longitudinal study of bidirectional causal relationship and its mediating and moderating variables in a Chinese student sample

While both sleep and optimism have been found to be predictive of well-being, few studies have examined their relationship with each other. Neither do we know much about the mediators and moderators of the relationship. This study investigated (1) the causal relationship between sleep quality and optimism in a college student sample, (2) the role of symptoms of depression, anxiety, and stress as mediators, and (3) how circadian preference might moderate the relationship. Internet survey data were collected from 1,684 full-time university students (67.6% female, mean age = 20.9 years, SD = 2.66) at three time-points, spanning about 19 months. Measures included the Attributional Style Questionnaire, the Pittsburgh Sleep Quality Index, the Composite Scale of Morningness, and the Depression Anxiety Stress Scale-21. Moderate correlations were found among sleep quality, depressive mood, stress symptoms, anxiety symptoms, and optimism. Cross-lagged analyses showed a bidirectional effect between optimism and sleep quality. Moreover, path analyses demonstrated that anxiety and stress symptoms partially mediated the influence of optimism on sleep quality, while depressive mood partially mediated the influence of sleep quality on optimism. In support of our hypothesis, sleep quality affects mood symptoms and optimism differently for different circadian preferences. Poor sleep results in depressive mood and thus pessimism in non-morning persons only. In contrast, the aggregated (direct and indirect) effects of optimism on sleep quality were invariant of circadian preference. Taken together, people who are pessimistic generally have more anxious mood and stress symptoms, which adversely affect sleep while morningness seems to have a specific protective effect countering the potential damage poor sleep has on optimism. In conclusion, optimism and sleep quality were both cause and effect of each other. Depressive mood partially explained the effect of sleep quality on optimism, whereas anxiety and stress symptoms were mechanisms bridging optimism to sleep quality. This was the first study examining the complex relationships among sleep quality, optimism, and mood symptoms altogether longitudinally in a student sample. Implications on prevention and intervention for sleep problems and mood disorders are discussed.

Sleep at baseline and after electroconvulsive therapy in patients with major depression

Sleep in major depressive disorder is frequently altered and possibly indicative for treatment outcomes. For example, increased rapid eye movement (REM-) sleep density seems to predict worse treatment outcomes of psychotherapy. We therefore investigated pre-treatment sleep and sleep changes after termination of electroconvulsive therapy (ECT). Sleep was polysomnographically recorded. The analysed sample consisted of 15 inpatients with ages ranging from 30 to 80 (mean 59 years). ECT was applied two times a week up to 7 weeks. Stable remission of depressive symptoms was defined by a score in the Hamilton Rating Scale of Depression <8 at six months after ECT. The main results were an increase in sleep efficiency and a decrease in the number of awakenings within the course of ECT in the entire patient group. Significant increases in slow wave sleep and REM sleep duration and a significant decrease in REM density were only seen in stable remitters and not in non-remitters. In pre-treatment baseline sleep a higher REM density of the first REM sleep period was significantly associated with better ECT outcome. In conclusion, REM density of the first REM sleep period seems to be an interesting candidate as putative predictor of stable treatment outcome of ECT.

Ablation of Type III Adenylyl Cyclase in Mice Causes Reduced Neuronal Activity, Altered Sleep Pattern, and Depression-like Phenotypes

BACKGROUND

Although major depressive disorder (MDD) has low heritability, a genome-wide association study in humans has recently implicated type 3 adenylyl cyclase (AC3; ADCY3) in MDD. Moreover, the expression level of AC3 in blood has been considered as a MDD biomarker in humans. Nevertheless, there is a lack of supporting evidence from animal studies.

METHODS

We employed multiple approaches to experimentally evaluate if AC3 is a contributing factor for major depression using mouse models lacking the Adcy3 gene.

RESULTS

We found that conventional AC3 knockout (KO) mice exhibited phenotypes associated with MDD in behavioral assays. Electroencephalography/electromyography recordings indicated that AC3 KO mice have altered sleep patterns characterized by increased percentage of rapid eye movement sleep. AC3 KO mice also exhibit neuronal atrophy. Furthermore, synaptic activity at cornu ammonis 3-cornu ammonis 1 synapses was significantly lower in AC3 KO mice, and they also exhibited attenuated long-term potentiation as well as deficits in spatial navigation. To confirm that these defects are not secondary responses to anosmia or developmental defects, we generated a conditional AC3 floxed mouse strain. This enabled us to inactivate AC3 function selectively in the forebrain and to inducibly ablate it in adult mice. Both AC3 forebrain-specific and AC3 inducible knockout mice exhibited prodepression phenotypes without anosmia.

CONCLUSIONS

This study demonstrates that loss of AC3 in mice leads to decreased neuronal activity, altered sleep pattern, and depression-like behaviors, providing strong evidence supporting AC3 as a contributing factor for MDD.

Validation of a Wireless, Self-Application, Ambulatory Electroencephalographic Sleep Monitoring Device in Healthy Volunteers

STUDY OBJECTIVES

To evaluate the validity of an ambulatory electroencephalographic (EEG) monitor for the estimation of sleep continuity and architecture in healthy adults.

METHODS

Healthy, good sleeping participants (n = 14) were fit with both an ambulatory EEG monitor (Sleep Profiler) and a full polysomnography (PSG) montage. EEG recordings were gathered from both devices on the same night, during which sleep was permitted uninterrupted for eight hours. The study was set in an inpatient clinical research suite. PSG and Sleep Profiler records were scored by a neurologist board certified in sleep medicine, blinded to record identification. Agreement between the scored PSG record, the physician-scored Sleep Profiler record, and the Sleep Profiler record scored by an automatic algorithm was evaluated for each sleep stage, with the PSG record serving as the reference.

RESULTS

Results indicated strong percent agreement across stages. Kappa was strongest for Stage N3 and REM. Specificity was high for all stages; sensitivity was low for Wake and Stage N1, and high for Stage N2, Stage N3, and REM. Agreement indices improved for the manually scored Sleep Profiler record relative to the autoscore record.

CONCLUSIONS

Overall, the Sleep Profiler yields an EEG record with comparable sleep architecture estimates to PSG. Future studies should evaluate agreement between devices with a clinical sample that has greater periods of wake in order to better understand utility of this device for estimating sleep continuity indices, such as sleep onset latency and wake after sleep onset.

A hypothetic aging pathway from skin to hypothalamic suprachiasmatic nucleus via slow wave sleep

Many observations have demonstrated that the hypothalamic neuroendocrine change determines the chronological sequence of aging in mammals. However, it remains uncertain on the mechanism to account for the hypothalamic aging manifestations. In this article, it is pointed out that, as constantly exposed to sunshine and oxygen, the skin would undergo both telomere-shortening and oxidative senescent processes. The senescent alterations of skin, such as attenuation in electrodermal activities, would in turn reduce the emotional responses and memories. Whereas previously I demonstrated that the slow wave sleep just functioned to adjust the emotional balance disrupted by accumulated emotional memories, especially capable of ameliorating the symptoms of depressed patients. Therefore, the reduction in emotional responses and memories from skin senescence would reduce the requirement for slow wave sleep in many senescent observations. The decrement in slow wave sleep would in further cause functional but not chronological degeneration of suprachiasmatic nucleus rather than paraventricular nucleus in hypothalamus. In these respects, from skin senescence to slow wave sleep, there forms a new degenerative aging pathway able to account for the hypothalamic chronological sequence of aging, specifically addressed to the suprachiasmatic nucleus.

Depression, anxiety, and tobacco use: Overlapping impediments to sleep in a national sample of college students

OBJECTIVES

To examine how tobacco use and depression/anxiety disorders are related to disturbed sleep in college students.

PARTICIPANTS

85,138 undergraduate respondents (66.3% female, 74.5% white, non-Hispanic, ages 18-25) from the Spring 2011 American College Health Association-National College Health Assessment II database.

METHODS

Multivariate analyses of tobacco use (none, intermediate, daily) and mental health (diagnosed and/or symptomatic depression or anxiety) were used to predict sleep disturbance.

RESULTS

Daily tobacco use was associated with more sleep problems than binge drinking, illegal drug use, obesity, gender, and working >20 hours/week. Students with depression or anxiety reported more sleep disturbances than individuals without either disorder, and tobacco use in this population was associated with the most sleep problems.

CONCLUSIONS

Tobacco use and depression/anxiety disorders are both independently associated with more sleep problems in college students. Students with depression and/or anxiety are more likely to be daily tobacco users, which likely exacerbates their sleep problems.

Hippocampal and motor fronto-cortical neuroligin1 is increased in an animal model of depression

Neuroligins (NLGNs) regulate synaptic excitability, neuronal signaling and sleep. We hypothesize that alteration of NLGNs is involved in the pathology of depression and tested the hypothesis in a model of depression using Wistar Kyoto (WKy) rat and its control, the Wistar (Wis) rat. We first evaluated behavioral deficits using the forced swim test and then characterized alterations of NLGN1 and NLGN2 with RT-PCR and Western Blotting in the prefrontal cortex, motor frontal cortex and hippocampus. Compared with controls of Wis rats, (1) the WKy rats had significantly shorter swim time and longer immobile time; (2) NLGN1 mRNA levels was higher in the motor frontal cortex and hippocampus in the WKy model; (3) NLGN1 protein was significantly higher in the motor frontal cortex, the prefrontal cortex and the hippocampus in the WKy model; (4) NLGN2 mRNA was significantly higher in the motor frontal cortex but significantly lower in the hippocampus in the WKy model. We concluded that NLGN1 gene and protein expression is higher in the motor frontal cortex, hippocampus and in the prefrontal cortex in the WKy rats suggesting that alterations of NLGN1 is involved in the pathology of depression but need to be further evaluated in human.

Sleep Architecture Relates to Daytime Affect and Somatic Complaints in Clinically Anxious but Not Healthy Children

It is increasingly clear that seminal sleep-affective relationships begin to take root in childhood, yet studies exploring how nighttime sleep characteristics relate to daytime affective symptoms, both in clinical and healthy populations of children, are lacking. The current study sought to explore these relationships by investigating whether trait-like and/or daily reports of affective and somatic symptoms of children with generalized anxiety disorder and matched controls relate to sleep architecture. Sixty-six children (ages 7-11; 54.4% female; 56.1% Caucasian; 18.2% biracial; 6.1% African American; 3% Asian; 16.7% Hispanic) participated including 29 with primary generalized anxiety disorder (without comorbid depression) and 37 healthy controls matched on age and race/ethnicity. Participants underwent structured diagnostic assessments including child-report measures and subsequently reported on their negative affect and somatic symptoms over the course of 1 week. Children also completed 1 night of polysomnography. Among children with generalized anxiety disorder only, greater amounts of slow wave sleep corresponded with less negative affect, and greater amounts of rapid eye movement sleep was related to more somatic complaints across the week. Similarly, for trait-like measures, more rapid eye movement sleep and shorter latency to rapid eye movement sleep were related to greater depressive symptoms in the anxious group only. The current findings suggest that physiologic sleep characteristics may contribute in direct ways to the symptom profiles of clinically anxious children. The functional relevance of such findings (e.g., how specific sleep characteristics serve to either increase or reduce long-term risk) is a vital direction for future research.

Sleep and mental disorders: A meta-analysis of polysomnographic research

Investigating sleep in mental disorders has the potential to reveal both disorder-specific and transdiagnostic psychophysiological mechanisms. This meta-analysis aimed at determining the polysomnographic (PSG) characteristics of several mental disorders. Relevant studies were searched through standard strategies. Controlled PSG studies evaluating sleep in affective, anxiety, eating, pervasive developmental, borderline and antisocial personality disorders, attention-deficit-hyperactivity disorder (ADHD), and schizophrenia were included. PSG variables of sleep continuity, depth, and architecture, as well as rapid-eye movement (REM) sleep were considered. Calculations were performed with the "Comprehensive Meta-Analysis" and "R" software. Using random effects modeling, for each disorder and each variable, a separate meta-analysis was conducted if at least 3 studies were available for calculation of effect sizes as standardized means (Hedges' g). Sources of variability, that is, sex, age, and mental disorders comorbidity, were evaluated in subgroup analyses. Sleep alterations were evidenced in all disorders, with the exception of ADHD and seasonal affective disorders. Sleep continuity problems were observed in most mental disorders. Sleep depth and REM pressure alterations were associated with affective, anxiety, autism and schizophrenia disorders. Comorbidity was associated with enhanced REM sleep pressure and more inhibition of sleep depth. No sleep parameter was exclusively altered in 1 condition; however, no 2 conditions shared the same PSG profile. Sleep continuity disturbances imply a transdiagnostic imbalance in the arousal system likely representing a basic dimension of mental health. Sleep depth and REM variables might play a key role in psychiatric comorbidity processes. Constellations of sleep alterations may define distinct disorders better than alterations in 1 single variable. (PsycINFO Database Record

Do changes in subjective sleep and biological rhythms predict worsening in postpartum depressive symptoms? A prospective study across the perinatal period

Abnormalities of sleep and biological rhythms have been widely implicated in the pathophysiology of major depressive disorder (MDD) and bipolar disorder (BD). However, less is known about the influence of biological rhythm disruptions across the perinatal period on postpartum depression (PPD). The objective of this study was to prospectively evaluate the relationship between subjective changes in both sleep and biological rhythms and worsening of depressive symptoms from pregnancy to the postpartum period in women with and without mood disorders. Eighty-three participants (38 euthymic women with a history of a mood disorder and 45 healthy controls) were studied. Participants completed subjective assessments of sleep (Pittsburgh Sleep Quality Index), biological rhythm disturbances (Biological Rhythms Interview of Assessment in Neuropsychiatry), and depressive symptoms (Edinburgh Postnatal Depression Scale) prospectively at two time points: third trimester of pregnancy and at 6-12 weeks postpartum. Multivariate regression analyses showed that changes in biological rhythms across the perinatal period predicted worsening of depressive symptoms in both groups. Moreover, women with a history of a mood disorder showed higher levels of sleep and biological rhythm disruption during both pregnancy and the postpartum period. These findings suggest that disruptions in biological rhythms during the perinatal period increase the risk for postpartum mood worsening in healthy pregnant as well as in pregnant women with a history of mood disorders.

Free Energy and Virtual Reality in Neuroscience and Psychoanalysis: A Complexity Theory of Dreaming and Mental Disorder

The main concepts of the free energy (FE) neuroscience developed by Karl Friston and colleagues parallel those of Freud's Project for a Scientific Psychology. In Hobson et al. (2014) these include an innate virtual reality generator that produces the fictive prior beliefs that Freud described as the primary process. This enables Friston's account to encompass a unified treatment-a complexity theory-of the role of virtual reality in both dreaming and mental disorder. In both accounts the brain operates to minimize FE aroused by sensory impingements-including interoceptive impingements that report compliance with biological imperatives-and constructs a representation/model of the causes of impingement that enables this minimization. In Friston's account (variational) FE equals complexity minus accuracy, and is minimized by increasing accuracy and decreasing complexity. Roughly the brain (or model) increases accuracy together with complexity in waking. This is mediated by consciousness-creating active inference-by which it explains sensory impingements in terms of perceptual experiences of their causes. In sleep it reduces complexity by processes that include both synaptic pruning and consciousness/virtual reality/dreaming in REM. The consciousness-creating active inference that effects complexity-reduction in REM dreaming must operate on FE-arousing data distinct from sensory impingement. The most relevant source is remembered arousals of emotion, both recent and remote, as processed in SWS and REM on "active systems" accounts of memory consolidation/reconsolidation. Freud describes these remembered arousals as condensed in the dreamwork for use in the conscious contents of dreams, and similar condensation can be seen in symptoms. Complexity partly reflects emotional conflict and trauma. This indicates that dreams and symptoms are both produced to reduce complexity in the form of potentially adverse (traumatic or conflicting) arousals of amygdala-related emotions. Mental disorder is thus caused by computational complexity together with mechanisms like synaptic pruning that have evolved for complexity-reduction; and important features of disorder can be understood in these terms. Details of the consilience among Freudian, systems consolidation, and complexity-reduction accounts appear clearly in the analysis of a single fragment of a dream, indicating also how complexity reduction proceeds by a process resembling Bayesian model selection.

A literature review of heart rate variability in depressive and bipolar disorders

OBJECTIVE

Autonomic nervous system dysfunction has the potential to adversely impact general medical health and is known to exist in a number of psychiatric disorders. It reflects alterations in the function of several regions of the central nervous system. Measurement of heart rate variability provides a non-invasive tool for studying autonomic function. While the literature relating to the technical process of heart rate variability and aspects of depressive disorders has been reviewed in the past, research relating to both depressive and bipolar disorders has not been comprehensively reviewed. This paper critically considers the published research in heart rate variability in both depressive and bipolar affective disorders.

METHOD

A literature search using Medline, EMBASE, PsycINFO, ProQuest Psychology and references included in published literature was conducted using the following keywords: 'heart rate variability and autonomic, combined with depression, depressive disorder, bipolar, mania and sleep'.

RESULTS

The evidence demonstrates that, using heart rate variability measures, significant distortions of autonomic function are evident in both depressive and bipolar disorders and from most of their pharmacological treatments.

CONCLUSION

The autonomic dysfunction evident in both unipolar and bipolar affective disorders, and many psychotropic medications, has significant implications for our understanding of the neurophysiology of these disorders, their treatment and associated general health.

REM sleep homeostasis in the absence of REM sleep: Effects of antidepressants

Most antidepressants suppress rapid eye movement (REM) sleep, which is thought to be important to brain function, yet the resulting REM sleep restriction is well tolerated. This study investigated the impact of antidepressants with different mechanisms of action, such as selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCA), on the regulation of REM sleep in rats. REM sleep was first demonstrated to be homeostatically regulated using 5, 8 and 10 h of REM-sleep specific restriction through EEG-triggered arousals, with an average of 91 ± 10% of lost REM sleep recovered following a 26-29 -hour recovery period. Acute treatment with the antidepressants paroxetine, citalopram and imipramine inhibited REM sleep by 84 ± 8, 84 ± 8 and 69 ± 9% respectively relative to vehicle control. The pharmacologically-induced REM sleep deficits by paroxetine and citalopram were not fully recovered, whereas, after imipramine the REM sleep deficit was fully compensated. Given the marked difference between REM sleep recovery following the administration of paroxetine, citalopram, imipramine and REM sleep restriction, the homeostatic response was further examined by pairing REM sleep specific restriction with the three antidepressants. Surprisingly, the physiologically-induced REM sleep deficits incurred prior to suppression of REM sleep by all antidepressants was consistently recovered. The data indicate that REM sleep homeostasis remains operative following subsequent treatment with antidepressants and is unaffected by additional pharmacological inhibition of REM sleep.

Sleep correlates of depression and anxiety in an elderly Asian population

BACKGROUND

Research looking at the association between sleep and psychiatric symptoms in elderly Asian populations is lacking. The present study examines the sleep correlates of depression and anxiety in a sample of cognitively healthy older adults.

METHODS

The Geriatric Depression Scale, Geriatric Anxiety Inventory, and the Pittsburgh Sleep Quality Index were administered to a community sample of elderly participants (n = 107; 81 women; Mage = 71.3 years, SD = 5.7) RESULTS: Geriatric Depression Scale and Geriatric Anxiety Inventory scores are both significantly correlated with sleep disturbance. Geriatric Depression Scale scores are uniquely associated with daytime dysfunction, and Geriatric Anxiety Inventory scores are uniquely associated with perceived sleep quality, sleep latency, and global Pittsburgh Sleep Quality Index scores.

CONCLUSIONS

Depression and anxiety in a cohort of elderly Asian subjects are associated with a number of sleep-related issues; both are related to a somewhat different profile of sleep problems.

Impaired Recognition of Facially Expressed Emotions in Different Groups of Patients with Sleep Disorders

Introduction

Recently it has been shown that acute sleep loss has a direct impact on emotional processing in healthy individuals. Here we studied the effect of chronically disturbed sleep on emotional processing by investigating two samples of patients with sleep disorders.

Methods

25 patients with psychophysiologic insomnia (23 women and 2 men, mean age: 51.6 SD; 10.9 years), 19 patients with sleep apnea syndrome (4 women and 15 men, mean age: 51.9; SD 11.1) and a control sample of 24 subjects with normal sleep (15women and 9 men, mean age 45.3; SD 8.8) completed a Facial Expressed Emotion Labelling (FEEL) task, requiring participants to categorize and rate the intensity of six emotional expression categories: anger, anxiety, fear, happiness, disgust and sadness. Differences in FEEL score and its subscales among the three samples were analysed using ANOVA with gender as a covariate.

Results

Both patients with psychophysiologic insomnia and patients with sleep apnea showed significantly lower performance in the FEEL test as compared to the control group. Differences were seen in the scales happiness and sadness. Patient groups did not differ from each other.

Conclusion

By demonstrating that previously known effects of acute sleep deprivation on emotional processing can be extended to persons experiencing chronically disturbed sleep, our data contribute to a deeper understanding of the relationship between sleep loss and emotions.

Sleep Disturbances and Depression in the Multi-Ethnic Study of Atherosclerosis

STUDY OBJECTIVES

We examined the association of objectively and subjectively measured sleep disturbances with depression, and explored if race/ethnicity, socioeconomic status, and sex modified these associations.

METHODS

We used data from the cross-sectional Multi-Ethnic Study of Atherosclerosis Sleep Study. Participants included 1,784 adults (ages 54-93 y), 36.8% non-Hispanic Whites, 28.0% African Americans, 23.7% Hispanics, 11.5% Chinese, and 46.0% males. Sleep was assessed with actigraphy, polysomnography, and self-report. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. We used relative risk regression to evaluate the association of sleep measures and depression (CES-D score ≥ 16) adjusting for site, sociodemographics, and behavioral and medical risk factors.

RESULTS

Overall, 14.5% had depression, 29.3% had insomnia symptoms, 14.1% had excessive daytime sleepiness (EDS), 15.1% had apnea-hypopnea index (AHI) ≥ 30, and 30.4% experienced short sleep (< 6 h). Depression was associated with short sleep duration (adjusted prevalence ratio [PR] = 1.47, 95% confidence interval [CI] = 1.11, 1.94), < 10% rapid eye movement [REM] sleep (PR = 1.57, 95% CI = 1.08, 2.27), ≥ 25% REM sleep (PR = 1.42, 95% CI = 1.03, 1.95), insomnia (PR = 1.83, 95% CI = 1.39, 2.40), excessive daytime sleepiness (EDS) (PR = 1.61, 95% CI = 1.19, 2.18), and AHI > 15 + EDS (PR = 1.55, 95% CI = 1.01, 2.39). Short sleep duration was associated with depression among those with high school education or beyond, but not among those with less education. Insomnia was more strongly associated with depression among men than women.

CONCLUSIONS

Sleep disturbances are associated with depression among middle-aged and older adults; these associations may be modified by education and sex. Future research should further test these hypotheses, evaluate whether early detection or treatment of sleep disturbances ameliorate depression, and explore subpopulation differences.

Subchronical treatment with Fluoxetine modifies the activity of the MCHergic and hypocretinergic systems. Evidences from peptide CSF concentration and gene expression

In the postero-lateral hypothalamus are located two neuronal systems that utilize the neuropeptides melanin-concentrating hormone (MCH) and hypocretins (also called orexins) as neuromodulators. These systems have reciprocal connections between them, and project throughout the central nervous system. MCH has been involved in the generation of sleep, mainly REM sleep, while hypocretins have a critical role in the generation of wakefulness. MCHergic activity is also involved in the pathophysiology of major depressive disorder (MD). In this regards, intracerebral administration of MCH promotes pro-depressive behaviors (i.e., immobility in the forced swimming test) and REM sleep hypersomnia, which is an important trait of depression. Furthermore, the antagonism of the MCHR-1 receptor has a reliable antidepressant effect, suggesting that MCH is a pro-depressive factor. Hypocretins have been also involved in mood regulation; however, their role in depression is still on debate. Taking these data into account, we explored whether systemic subchronical treatment with Fluoxetine (FLX), a serotonergic antidepressant, modifies the concentration of MCH in the cerebrospinal fluid (CSF), as well as the preproMCH mRNA expression. We also evaluated the hypocretinergic system by quantifying the hypocretin-levels in the CSF and the preprohypocretin mRNA expression. Compared to control, FLX increased the levels of preprohypocretin mRNA without affecting the hypocretin-1 CSF levels. On the contrary, FLX significantly decreased the MCH CSF concentration without affecting the preproMCH gene expression. This result is in agreement with the fact that MCH serum level diminishes during the antidepressant treatment in MD, and supports the hypothesis that an increase in the MCHergic activity could have pro-depressive consequences.

Sex differences in sleep, anhedonia, and HPA axis activity in a rat model of chronic social defeat

Repeated bouts of a major stressor such as social defeat are well known to induce a depression phenotype in male rats. Despite strong evidence and acknowledgement that women have a two-fold lifetime greater risk of developing major depression compared to men, the inclusion of female rats in studies employing social defeat are very rare; their absence is attributed to less aggressive interactions. This study sought to compare in male and female rats the impact of repeated social defeat, three times per week for four weeks, on the development of changes in sleep architecture and continuity, sucrose preference as a measure of anhedonia, changes in body weight, and basal plasma corticosterone levels. We found significant reductions in rapid eye movement sleep (REMS) during the light phase in both females and males, and significant increases in numbers of vigilance state transitions during the early dark phase in females but not in males. Additionally, females exhibited significantly greater reductions in sucrose intake than males. On the other hand, no sex differences in significantly elevated basal corticosterone levels were evident, and only the males exhibited changes in body weight. Taken together these findings suggest that the inclusion of female rats in studies of social defeat may offer greater insights in studies of stress and depression.

Depression as a systemic syndrome: mapping the feedback loops of major depressive disorder

BACKGROUND

Depression is a complex public health problem with considerable variation in treatment response. The systemic complexity of depression, or the feedback processes among diverse drivers of the disorder, contribute to the persistence of depression. This paper extends prior attempts to understand the complex causal feedback mechanisms that underlie depression by presenting the first broad boundary causal loop diagram of depression dynamics.

METHOD

We applied qualitative system dynamics methods to map the broad feedback mechanisms of depression. We used a structured approach to identify candidate causal mechanisms of depression in the literature. We assessed the strength of empirical support for each mechanism and prioritized those with support from validation studies. Through an iterative process, we synthesized the empirical literature and created a conceptual model of major depressive disorder.

RESULTS

The literature review and synthesis resulted in the development of the first causal loop diagram of reinforcing feedback processes of depression. It proposes candidate drivers of illness, or inertial factors, and their temporal functioning, as well as the interactions among drivers of depression. The final causal loop diagram defines 13 key reinforcing feedback loops that involve nine candidate drivers of depression.

CONCLUSIONS

Future research is needed to expand upon this initial model of depression dynamics. Quantitative extensions may result in a better understanding of the systemic syndrome of depression and contribute to personalized methods of evaluation, prevention and intervention.

Top-down control of arousal and sleep: Fundamentals and clinical implications

Mammalian sleep emerges from attenuated activity in the ascending reticular arousal system (ARAS), the main arousal network of the brain. This system originates in the brainstem and activates the thalamus and cortex during wakefulness via a well-characterized 'bottom-up' pathway. Recent studies propose that a less investigated cortico-thalamic 'top-down' pathway also regulates sleep. The present work integrates the current evidence on sleep regulation with a focus on the 'top-down' pathway and explores the potential to translate this information into clinically relevant interventions. Specifically, we elaborate the concept that arousal and sleep continuity in humans can be modulated by non-invasive brain stimulation (NIBS) techniques that increase or decrease cortical excitability. Based on preclinical studies, the modulatory effects of the stimulation are thought to extend to subcortical arousal networks. Further exploration of the 'top-down' regulation of sleep and its modulation through non-invasive brain stimulation techniques may contribute to the development of novel treatments for clinical conditions of disrupted arousal and sleep, which are among the major health problems worldwide.

A pilot study of serotonin-1A receptor genotypes and rapid eye movement sleep sensitivity to serotonergic/cholinergic imbalance in humans: a pharmacological model of depression

RATIONALE

The serotonergic and cholinergic systems are jointly involved in regulating sleep but this system is theorized to be disturbed in depressed individuals. We previously reported that cholinergic and serotonergic agents induce sleep changes partially consistent with monoamine models of sleep disturbances in depression. One potential cause of disturbed neurotransmission is genetic predisposition. The G(-1019) allele of the serotonin-1A (5-HT1A) receptor promoter region predicts an increased risk for depression compared to the wild-type C(-1019) allele.

OBJECTIVE

The goal of this study was to investigate how serotonin-1A receptor genotypes mediate sleep sensitivity to pharmacological probes modeling the serotonergic/cholinergic imbalance of depression.

METHODS

Seventeen healthy female participants homozygous for either C (n=11) or G (n=6) alleles aged 18-27 years were tested on four nonconsecutive nights. Participants were given galantamine (an anti-acetylcholinesterase), buspirone (a serotonergic agonist), both drugs together, or placebos before sleeping.

RESULTS

As reported previously, buspirone significantly increased rapid eye movement (REM) latency (P<0.001), as well as awakenings, percentage of time spent awake, and percentage of time asleep spent in stage N1 (P<0.019). Galantamine increased awakenings, percentage of time spent awake, percentage of time asleep spent in stage N1, and percentage of time asleep spent in REM, and decreased REM latency and percentage of time asleep spent in stage N3 (P<0.019). Galantamine plus buspirone given together disrupted sleep more than either drug alone, lowering sleep efficiency and percentage of time asleep spent in stage N3 and increasing awakenings, percentage of time spent awake, and percentage of time asleep spent in stage N1 (P<0.019). There was no main effect of genotype nor was there a significant multivariate interaction between genotype and drug condition.

CONCLUSION

These findings are partially consistent with the literature about sleep in depression, notably short REM latency, higher percentage of total sleep time spent in REM, lower percentage of time asleep spent in stage N3, and increased sleep fragmentation. The C/G mutation in the serotonin-1A receptor promoter region does not appear to cause noticeable differences in the sleep patterns of a relatively small sample of healthy young females. Future studies with larger sample sizes are required.

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.

Melanin-Concentrating Hormone (MCH): Role in REM Sleep and Depression

The melanin-concentrating hormone (MCH) is a peptidergic neuromodulator synthesized by neurons of the lateral sector of the posterior hypothalamus and zona incerta. MCHergic neurons project throughout the central nervous system, including areas such as the dorsal (DR) and median (MR) raphe nuclei, which are involved in the control of sleep and mood. Major Depression (MD) is a prevalent psychiatric disease diagnosed on the basis of symptomatic criteria such as sadness or melancholia, guilt, irritability, and anhedonia. A short REM sleep latency (i.e., the interval between sleep onset and the first REM sleep period), as well as an increase in the duration of REM sleep and the density of rapid-eye movements during this state, are considered important biological markers of depression. The fact that the greatest firing rate of MCHergic neurons occurs during REM sleep and that optogenetic stimulation of these neurons induces sleep, tends to indicate that MCH plays a critical role in the generation and maintenance of sleep, especially REM sleep. In addition, the acute microinjection of MCH into the DR promotes REM sleep, while immunoneutralization of this peptide within the DR decreases the time spent in this state. Moreover, microinjections of MCH into either the DR or MR promote a depressive-like behavior. In the DR, this effect is prevented by the systemic administration of antidepressant drugs (either fluoxetine or nortriptyline) and blocked by the intra-DR microinjection of a specific MCH receptor antagonist. Using electrophysiological and microdialysis techniques we demonstrated also that MCH decreases the activity of serotonergic DR neurons. Therefore, there are substantive experimental data suggesting that the MCHergic system plays a role in the control of REM sleep and, in addition, in the pathophysiology of depression. Consequently, in the present report, we summarize and evaluate the current data and hypotheses related to the role of MCH in REM sleep and MD.

Diet/Energy Balance Affect Sleep and Wakefulness Independent of Body Weight

STUDY OBJECTIVES

Excessive daytime sleepiness commonly affects obese people, even in those without sleep apnea, yet its causes remain uncertain. We sought to determine whether acute dietary changes could induce or rescue wake impairments independent of body weight.

DESIGN

We implemented a novel feeding paradigm that generates two groups of mice with equal body weight but opposing energetic balance. Two subsets of mice consuming either regular chow (RC) or high-fat diet (HFD) for 8 w were switched to the opposite diet for 1 w. Sleep recordings were conducted at Week 0 (baseline), Week 8 (pre-diet switch), and Week 9 (post-diet switch) for all groups. Sleep homeostasis was measured at Week 8 and Week 9.

PARTICIPANTS

Young adult, male C57BL/6J mice.

MEASUREMENTS AND RESULTS

Differences in total wake, nonrapid eye movement (NREM), and rapid eye movement (REM) time were quantified, in addition to changes in bout fragmentation/consolidation. At Week 9, the two diet switch groups had similar body weight. However, animals switched to HFD (and thus gaining weight) had decreased wake time, increased NREM sleep time, and worsened sleep/wake fragmentation compared to mice switched to RC (which were in weight loss). These effects were driven by significant sleep/wake changes induced by acute dietary manipulations (Week 8 → Week 9). Sleep homeostasis, as measured by delta power increase following sleep deprivation, was unaffected by our feeding paradigm.

CONCLUSIONS

Acute dietary manipulations are sufficient to alter sleep and wakefulness independent of body weight and without effects on sleep homeostasis.

Sleep Disturbances in Mood Disorders

The article provides an overview of common and differentiating self-reported and objective sleep disturbances seen in mood-disordered populations. The importance of considering sleep disturbances in the context of mood disorders is emphasized, because a large body of evidence supports the notion that sleep disturbances are a risk factor for onset, exacerbation, and relapse of mood disorders. In addition, potential mechanisms for sleep disturbance in depression, other primary sleep disorders that often occur with mood disorders, effects of antidepressant and mood-stabilizing drugs on sleep, and the adjunctive effect of treating sleep in patients with mood disorders are discussed.

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.

The Effects of Sleep Continuity Disruption on Positive Mood and Sleep Architecture in Healthy Adults

OBJECTIVE

The purpose of this study was to test an experimental model of the effects of sleep continuity disturbance on sleep architecture and positive mood in order to better understand the mechanisms linking insomnia and depression.

DESIGN

Participants were randomized to receive 3 consecutive nights of sleep continuity disruption via forced nocturnal awakenings (FA, n = 21), or one of two control conditions: restricted sleep opportunity (RSO, n = 17) or uninterrupted sleep (US, n = 24).

SETTING

The study was set in an inpatient clinical research suite.

PARTICIPANTS

Healthy, good-sleeping men and women were included.

MEASUREMENT AND RESULTS

Polysomnography was used to measure sleep architecture, and mood was assessed via self-report each day. Compared to restricted sleep opportunity controls, forced awakenings subjects had significantly less slow wave sleep (P < 0.05) after the first night of sleep deprivation, and significantly lower positive mood (P < 0.05) after the second night of sleep deprivation. The differential change in slow wave sleep statistically mediated the observed group differences in positive mood (P = 0.002).

CONCLUSIONS

To our knowledge, this is the first human experimental study to demonstrate that, despite comparable reductions in total sleep time, partial sleep loss from sleep continuity disruption is more detrimental to positive mood than partial sleep loss from delaying bedtime, even when controlling for concomitant increases in negative mood. With these findings, we provide temporal evidence in support of a putative biologic mechanism (slow wave sleep deficit) that could help explain the strong comorbidity between insomnia and depression.

Self-reported sleep in late pregnancy in relation to birth size and fetal distress: the E Moe, Māmā prospective cohort study

OBJECTIVES

To explore associations between features of sleep during pregnancy and adverse outcomes for the infant.

SETTING

E Moe, Māmā is a cohort study in Aotearoa/New Zealand that investigates self-reported sleep and maternal health in late pregnancy and the postpartum period.

PARTICIPANTS

Women (N=633; 194 Māori) reported detailed information on their sleep duration, quality, disturbances, disorders (snoring, breathing pauses, twitching legs, restless legs) and daytime sleepiness between 35 and 37 weeks gestation.

OUTCOME MEASURES

Birthweight and fetal distress during labour were extracted from medical records. Associations between each sleep variable and small or large for gestational age (SGA/LGA) using customised birthweight centile or fetal distress were estimated using multinomial/logistic regression, controlling for potential confounders. Secondary analyses considered differences in associations between Māori and non-Māori women.

RESULTS

There was some indication that breathing pauses (a measure of sleep apnoea) were associated with both SGA (OR 2.8, 95% CI 0.9 to 9.0, p=0.08) and LGA (OR 2.0, 95% CI 0.7 to 5.7, p=0.20), with the association for LGA being stronger when only pregnancy-onset breathing pauses were considered (OR 3.5, 95% CI 1.3 to 9.6, p=0.01). There was also some evidence that pregnancy-onset leg twitching (OR 3.3, 95% CI 1.1 to 10.0, p=0.03) and frequent sleep disturbance due to feeling too hot or too cold (OR 1.7, 95% CI 0.9 to 3.6, p=0.13) were associated with higher risk of fetal distress. Other sleep measures, including snoring, were not associated with SGA, LGA or fetal distress. Many of the associations we observed were considerably stronger in Māori compared with non-Māori women.

CONCLUSIONS

We did not find evidence of previously reported associations between snoring and SGA. Our findings tentatively suggest that self-reported breathing pauses and leg twitching in late pregnancy are associated with infant outcomes, and highlight ethnic inequalities.

The effects of galantamine and buspirone on sleep structure: Implications for understanding sleep abnormalities in major depression

RATIONALE

The serotonergic and cholinergic systems are jointly involved in regulating sleep, but this balance is theorized to be disturbed in depressed individuals.

OBJECTIVE

The goal of this study was to use biological probes in healthy participants, to model the serotonergic/cholinergic imbalance of depression and its associated abnormalities in sleep structure.

METHODS

We tested 20 healthy female participants 18-30 years of age on four non-consecutive nights. Participants were given galantamine (a cholinergic agent), buspirone (a serotonergic agonist), both drugs together, or placebo before sleeping.

RESULTS

Buspirone suppressed tonic rapid eye movement (REM): There was a significant increase in REM latency (p < 0.001). Galantamine increased tonic REM sleep, leading to more time spent in REM (p < 0.001) and shorter REM latency (p < 0.01). Galantamine and buspirone given together were not significantly different from the placebo night by REM sleep measures, but disrupted sleep more than either drug alone.

CONCLUSIONS

These findings are partially consistent with the cholinergic literature about sleep in depression, notably short REM latency, higher percentage of total sleep time spent in REM and increased sleep fragmentation. The prolonged REM latency and reduced percentage of REM with buspirone resembled the effect of selective serotonin reuptake inhibitor antidepressants on REM sleep.

Dynamics of melanin-concentrating hormone (MCH) serum levels in major depressive disorder during antidepressant treatment

BACKGROUND

In preclinical studies, the hypothalamic polypeptide melanin-concentrating hormone (MCH) has been shown to be involved in depression-like behavior and modulations of MCH and MCH-receptors were proposed as potential new antidepressant drug targets.

METHODS

For the first time, MCH serum levels were explored in 30 patients with major depressive disorder (MDD) prior to (T1) and after 2 (T2) and 4 weeks (T3) of antidepressant treatment and in 30 age- and sex-matched healthy controls by applying a fluorescence immunoassay.

RESULTS

Levels of MCH did not differ significantly between un-medicated patients (444.11±174.63pg/mL SD) and controls (450.68±210.03pg/mL SD). In MDD patients, MCH levels significantly decreased from T1 to T3 (F=4.663; p=0.013). Post-hoc analyses showed that these changes were limited to patients treated with mirtazapine but not escitalopram and female but not male patients. MCH-levels showed high correlations from T1 to T3 (r≥0.964, p<0.001) and were found to correlate significantly with parameters of sleep within the controls.

LIMITATIONS

Small sample size. No follow-up measures were performed within the control group.

CONCLUSIONS

Our findings suggest peripheral MCH-levels not to be altered in depression but possibly reflecting depression-related state properties that can be modulated by sleep, medication and sex.

Schizophrenia and Depression: A systematic Review of the Effectiveness and the Working Mechanisms Behind Acupuncture

OBJECTIVE

This systematic review assessed clinical evidence for the use of acupuncture as an add-on treatment in patients with depression and schizophrenia and for its underlying working mechanisms.

DATA SOURCES

Four databases (Medline, Scopus, ERIC, and the Cochrane Library) were searched with a cutoff date of March 31, 2014.

STUDY SELECTION

Systematic reviews and meta-analyses of acupuncture treatment for depression and schizophrenia were considered for inclusion. The scarcity of acupuncture research involving schizophrenia led to the inclusion of randomized controlled trials and case studies.

DATA EXTRACTION

The primary and secondary aims of this study were to evaluate the effects of acupuncture in treating patients with depression or schizophrenia and the possible working mechanisms underlying acupuncture through a systematic literature review.

DATA SYNTHESIS

The overall clinical results on using acupuncture to treat depression are promising, but only limited evidence for its effectiveness in treating schizophrenia was found. Acupuncture improves the quality of life, particularly that of sleep, in psychiatric patients. Brain research has revealed that acupuncture has a modulating and normalizing effect on the limbic-paralimbic-neocortical network (LPNN), including the default mode network. Because the LPNN is related to sleep and emotions, this might explain the improved qualities of life and sleep after acupuncture.

CONCLUSIONS

From the evidence found in this study, acupuncture seems to be an effective add-on treatment in patients with depression and, to a lesser degree, in patients with schizophrenia, but large well-designed studies are needed to confirm that evidence.

Sleep in adolescent depression: physiological perspectives

Depression and disturbed sleep are intimately and bidirectionally related. During adolescence, the incidence of both insomnia and major depression increases simultaneously, in a gender-specific manner. The majority of depressed adolescents suffer from different types of subjective sleep complaints. Despite these complaints, the results from polysomnographic studies in depressed adolescents remain inconsistent. In general, similar features to those seen among adults with depressive disorder (e.g. abnormalities in rapid eye movement sleep and difficulties in sleep onset) have been reported, but expressed to a lesser degree. The inconsistency in findings may be linked with maturational factors, factors related to the stage of illness and greater heterogeneity in the clinical spectrum of depression among adolescents. The exact neurobiological mechanisms by which sleep alterations and depression are linked during adolescence are not fully understood. Aberrations in brain maturation, expressed at different levels of organization, for example gene expression, neurotransmitter and hormone metabolism, and activity of neuronal networks have been suggested. The circadian systems may change in adolescent depression beyond that observed during healthy adolescent development (i.e. beyond the typical circadian shift towards eveningness). A number of therapeutic approaches to alleviate sleep disruption associated with depression have been proposed, but research on the efficacy of these interventions in adolescents is lacking. Knowledge of the neurobiological links between sleep and depression during adolescence could lead to new insights into effective prevention and treatment of depression.

Elevated Hippocampal Cholinergic Neurostimulating Peptide precursor protein (HCNP-pp) mRNA in the amygdala in major depression

The amygdala is innervated by the cholinergic system and is involved in major depressive disorder (MDD). Evidence suggests a hyper-activate cholinergic system in MDD. Hippocampal Cholinergic Neurostimulating Peptide (HCNP) regulates acetylcholine synthesis. The aim of the present work was to investigate expression levels of HCNP-precursor protein (HCNP-pp) mRNA and other cholinergic-related genes in the postmortem amygdala of MDD patients and matched controls (females: N = 16 pairs; males: N = 12 pairs), and in the mouse unpredictable chronic mild stress (UCMS) model that induced elevated anxiety-/depressive-like behaviors (females: N = 6 pairs; males: N = 6 pairs). Results indicate an up-regulation of HCNP-pp mRNA in the amygdala of women with MDD (p < 0.0001), but not males, and of UCMS-exposed mice (males and females; p = 0.037). HCNP-pp protein levels were investigated in the human female cohort, but no difference was found. There were no differences in gene expression of acetylcholinesterase (AChE), muscarinic (mAChRs) or nicotinic receptors (nAChRs) between MDD subjects and controls or UCMS and control mice, except for an up-regulation of AChE in UCMS-exposed mice (males and females; p = 0.044). Exploratory analyses revealed a baseline expression difference of cholinergic signaling-related genes between women and men (p < 0.0001). In conclusion, elevated amygdala HCNP-pp expression may contribute to mechanisms of MDD in women, potentially independently from regulating the cholinergic system. The differential expression of genes between women and men could also contribute to the increased vulnerability of females to develop MDD.

New data on psychological traits and sleep profiles of patients affected by nocturnal eating

OBJECTIVE

Nocturnal eating behavior is shared by patients affected by a parasomnia, sleep-related eating disorder (SRED), and several eating disorders such as night eating syndrome (NES) and binge-eating disorder (BED); however, the differential clinical features of these patients have been poorly studied, with persisting difficulties in defining the borders between these pathologies. The aim of this study was to evaluate polysomnographic and personality characteristics of nocturnal eaters to further differentiate the syndromes.

METHODS

During a period of six months, consecutive patients complaining of nocturnal eating were asked to participate to the study. Twenty-four patients who were found to eat during the polysomnographic recording (PSG) study, and gender-matched control subjects were included. All subjects underwent a full-night video-PSG study and a psychometric assessment including the Eating Disorder Inventory (EDI-2), the self-rating Bulimic Investigatory Test-Edinburgh (BITE), the Temperament and Character Inventory (TCI), and the Barratt Impulsivity Scale (BIS).

RESULTS

Nocturnal eaters showed a mild reduction in sleep efficiency and duration due to a moderate sleep fragmentation, whereas the percentage of each sleep stage was not significantly affected. Nocturnal eaters scored higher at many subscales of the EDI-2, at the BITE symptoms subscale, and at the BIS attentional impulsivity subscale.

CONCLUSION

The psychological characteristics found in our patients with NES seem to be typical for patients affected by eating disorders, and support the hypothesis that the nocturnal behavior of these individuals is due to an eating disorder; however, specific traits also allow differentiation of NES from BED.

The Neurobiological Mechanisms and Treatments of REM Sleep Disturbances in Depression

Most depressed patients suffer from sleep abnormalities, which are one of the critical symptoms of depression. They are robust risk factors for the initiation and development of depression. Studies about sleep electroencephalograms have shown characteristic changes in depression such as reductions in non-rapid eye movement sleep production, disruptions of sleep continuity and disinhibition of rapid eye movement (REM) sleep. REM sleep alterations include a decrease in REM sleep latency, an increase in REM sleep duration and REM sleep density with respect to depressive episodes. Emotional brain processing dependent on the normal sleep-wake regulation seems to be failed in depression, which also promotes the development of clinical depression. Also, REM sleep alterations have been considered as biomarkers of depression. The disturbances of norepinephrine and serotonin systems may contribute to REM sleep abnormalities in depression. Lastly, this review also discusses the effects of different antidepressants on REM sleep disturbances in depression.

The truncated TrkB receptor influences mammalian sleep

Brain-derived neurotrophic factor (BDNF) is a neurotrophin hypothesized to play an important role in mammalian sleep expression and regulation. In order to investigate the role of the truncated receptor for BDNF, TrkB.T1, in mammalian sleep, we examined sleep architecture and sleep regulation in adult mice constitutively lacking this receptor. We find that TrkB.T1 knockout mice have increased REM sleep time, reduced REM sleep latency, and reduced sleep continuity. These results demonstrate a novel role for the TrkB.T1 receptor in sleep expression and provide new insights into the relationship between BDNF, psychiatric illness, and sleep.

Sleep complaints in adolescent depression: one year naturalistic follow-up study

BACKGROUND

Sleep complaints are highly prevalent in adolescents suffering from major depressive disorder (MDD). The aims of this study were to describe the longitudinal course of sleep complaints, and to assess the association between sleep complaints and clinical outcome in a sample of adolescents with MDD during naturalistic follow-up.

METHODS

A sample of adolescent outpatients (n = 166; age 13-19 years, 17.5% boys) diagnosed with MDD was followed-up during one year in naturalistic settings. Sleep symptoms and psychiatric symptoms were assessed with interviews and self-report questionnaires.

RESULTS

All sleep complaints were less frequent at one-year follow-up compared to baseline. Baseline sleep complaints did not adversely affect clinical outcome at one-year follow-up: severity of the sleep complaints at baseline was associated with a steeper improvement of depressive and anxiety symptoms, suicidality/self-harm symptoms, and overall psychosocial functioning over time.

CONCLUSIONS

Our results suggest that sleep disturbances at baseline do not necessarily lead to poorer clinical outcome during follow-up. Larger longitudinal studies combining both subjective and objective measures of sleep in depressed adolescents are needed to clarify the link between sleep and depression further.

Psychiatric disorders and sleep issues

Sleep issues are common in people with psychiatric disorders, and the interaction is complex. Sleep disorders, particularly insomnia, can precede and predispose to psychiatric disorders, can be comorbid with and exacerbate psychiatric disorders, and can occur as part of psychiatric disorders. Sleep disorders can mimic psychiatric disorders or result from medication given for psychiatric disorders. Impairment of sleep and of mental health may be different manifestations of the same underlying neurobiological processes. For the primary care physician, key tools include recognition of potential sleep effects of psychiatric medications and familiarity with treatment approaches for insomnia in depression and anxiety.

Poor sleep quality in systemic lupus erythematosus: does it depend on depressive symptoms?

Objectives

Sleep disturbances are frequently observed in rheumatic diseases including systemic lupus erythematosus (SLE). This study aimed at evaluating the prevalence of insomnia, poor sleep quality and their determinants in a cohort of SLE patients.

Methods

Eighty-one consecutive SLE female patients were evaluated in a cross-sectional study. The Pittsburgh Sleep Quality Index (PSQI), the Insomnia Severity Index (ISI), the Beck Depression Inventory (BDI) and the Self-rating Anxiety Scale (SAS) were administered. Patients with previous diagnosis of obstructive sleep apnea or restless legs syndrome were excluded. Fifty-three women with hypertension (without SLE) were enrolled as control group (H).

Results

In the SLE cohort poor sleep quality (65.4% vs 39.6%, p < 0.01) and difficulty in maintaining sleep and/or early morning awakening (65.4% vs 22.6%, p < 0.001), but not insomnia (33.3% vs 22.6%, p = ns), were more prevalent than in H. Depressive symptoms were present in 34.6% of SLE vs 13.2% H patients ( p < 0.001) while state anxiety was more common in H patients (H 35.8% vs SLE 17.3%, p < 0.005). SLE was associated with a 2.5-times higher probability of presenting poor sleep quality in comparison to H (OR 2.5 [CI 1.21–5.16]). After adjusting for confounders, both depressive symptoms (OR 4.4, [1.4–14.3]) and use of immunosuppressive drugs (OR 4.3 [CI 1.3–14.8]) were significantly associated with poor sleep quality in SLE patients. Furthermore, poor sleep quality was not associated either with disease duration or activity.

Conclusions

In a cohort of SLE women, insomnia and poor sleep quality, especially difficulties in maintaining sleep, were common. Depressive symptoms might be responsible for the higher prevalence of poor sleep quality in SLE.