Sleep architecture variation: a mediator of metabolic disturbance in individuals with major depressive disorder

A REM-active basal ganglia circuit that regulates anxiety

Rapid eye movement (REM) sleep has been hypothesized to promote emotional resilience, but any neuronal circuits mediating this have not been identified. We find that in mice, somatostatin (Som) neurons in the entopeduncular nucleus (EPSom)/internal globus pallidus are predominantly active during REM sleep. This unique REM activity is both necessary and sufficient for maintaining normal REM sleep. Inhibiting or exciting EPSom neurons reduced or increased REM sleep duration, respectively. Activation of the sole downstream target of EPSom neurons, Vglut2 cells in the lateral habenula (LHb), increased sleep via the ventral tegmental area (VTA). A simple chemogenetic scheme to periodically inhibit the LHb over 4 days selectively removed a significant amount of cumulative REM sleep. Chronic, but not acute, REM reduction correlated with mice becoming anxious and more sensitive to aversive stimuli. Therefore, we suggest that cumulative REM sleep, in part generated by the EP → LHb → VTA circuit identified here, could contribute to stabilizing reactions to habitual aversive stimuli.

Sleep architecture and the incidence of depressive symptoms in middle-aged and older adults: A community-based study

BACKGROUND

Rapid eye movement (REM) sleep and three stages of non-REM (NREM) sleep comprise the full sleep cycle. The changes in sleep have been linked to depression risk. This study aimed to explore the association between sleep architecture and depressive symptoms.

METHODS

A total of 3247 participants from the Sleep Heart Health Study (SHHS) were included in this cohort study. REM and NREM sleep were monitored by in-home polysomnography at SHHS visit 1. Depressive symptoms was reported as the first occurrence between SHHS visits 1 and 2 (mean follow-up of 5.3 years). Multivariable logistic regression was used to investigate the relationship between sleep stages and depressive symptoms.

RESULTS

In total, 225 cases of depressive symptoms (6.9 %) were observed between SHHS visits 1 and 2. A significant linear association between NREM Stage 1 and depressive symptoms was found after adjusting for potential covariates. Multivariable logistic regression analysis showed that percentage in NREM Stage 1 was associated with the incidence of depressive symptoms (odds ratio [OR], 1.06; 95 % confidence interval [CI], 1.02-1.10; P = 0.001), as were time in NREM Stage 1 and depressive symptoms (OR, 1.02; 95 % CI, 1.01-1.03; P = 0.001). However, no significant association with depressive symptoms was found for other sleep stage.

LIMITATIONS

The specific follow-up time for depressive symptoms diagnosis was missing.

CONCLUSIONS

Increased time or percentage in NREM Stage 1 was associated with a higher risk of developing depressive symptoms. The early change in sleep architecture were important for incidence of depressive symptoms and warrants constant concerns.

Dyadic sleep intervention for adult patients with cancer and their sleep-partner caregivers: A feasibility study

OBJECTIVES

Sleep disturbances are common among adult patients with cancer and their caregivers. To our knowledge, no sleep intervention to date has been designed to be provided to both patients with cancer and their caregivers simultaneously. This single-arm study aimed to pilot test the feasibility and acceptability, and to illustrate the preliminary efficacy on sleep efficiency of the newly developed dyadic sleep intervention, My Sleep Our Sleep (MSOS: NCT04712604).

METHODS

Adult patients who were newly diagnosed with a gastrointestinal (GI) cancer and their sleep-partner caregivers (n = 20 persons: 10 dyads, 64 years old, 60% female patients, 20% Hispanic, 28 years relationship duration), both of whom had at least mild levels of sleep disturbance (Pittsburgh Sleep Quality Index [PSQI] ≥ 5) participated in this study. MSOS intervention consists of four 1-hour weekly sessions delivered using Zoom to the patient-caregiver dyad together.

RESULTS

We were able to enroll 92.9% of the eligible and screened patient-caregiver dyads within 4 months. Participants reported high satisfaction in 8 domains (average 4.76 on a 1-5 rating). All participants agreed that the number of sessions, interval (weekly), and delivery mode (Zoom) were optimal. Participants also preferred attending the intervention with their partners. Both patients and caregivers showed improvement in sleep efficiency after completing the MSOS intervention: Cohen's d = 1.04 and 1.47, respectively.

SIGNIFICANCE OF RESULTS

Results support the feasibility and acceptability, as well as provide the preliminary efficacy of MSOS for adult patients with GI cancer and their sleep-partner caregivers. Findings suggest the need for more rigorous controlled trial designs for further efficacy testing of MSOS intervention.

The mediating effect of sleep disturbance on the association between hypertension and depression: a national data analysis

BACKGROUND

Sleep disturbance is a common among people with hypertension. However, the mediating role of sleep disturbance in the association between hypertension and depression remains unclear. This study aims to investigate the mediating role of sleep disturbance in the association between hypertension and depression.

MATERIALS AND METHODS

This was cross-sectional study. The data were derived from the Indonesian Family Life Survey Fifth Wave (2014-2015). We include a total of 19,138 adults' participants with age range from 18 to 65 years old who completed response on the variable of hypertension, sleep disturbance, and depression. The mediating model analysis was processed using the PROCESS macro ins SPSS from Hayes model.

RESULTS

Depression was reported by 22% of total respondents. The group with hypertension showed a substantially higher prevalence of depression than non-hypertension group (P < 0.001). Hypertension had a significant overall effect on depression (β = 0.682; 95%CI 0.489 to 0.875, P < 0.001). The direct effect of hypertension on depression was significant (β = 0.418; 95%CI 0.244 to 0.592, P < 0.001) and the indirect effect that mediated by sleep disturbance was also significant (β = 0.264, 95%CI 0.174 to 0.356, P < 0.001). It is worth noting that sleep disturbance partially mediated the association between hypertension and depression.

CONCLUSION

The findings of this study indicated that sleep disturbance contributed to the etiology of depression and hypertension in adult populations. Nurses should be involved in managing sleep disturbances, such as using behavioral therapy, as it may serve as both a treatment and primary prevention measure for depression and hypertension.

Exploring the role of inflammation in major depressive disorder: beyond the monoamine hypothesis

Major depressive disorder affects approximately 8.4% of the United States population. The World Health Organization estimates that 280 million adults worldwide are suffering from depression. They have estimated that by 2030 it will be the second most serious condition. Current treatment relies on the monoamine hypothesis, however, one-third of patients with MDD do not respond to monoamine-based antidepressants. For years, it was hypothesized that the primary pathway of MDD involved serotonin as the main neurotransmitter. The monoamine hypothesis, a widely accepted theory, sought to explain the biological basis of MDD as being caused by the depletion of monoamine neurotransmitters, namely norepinephrine and serotonin. This hypothesis regarding monoamines as the pathophysiological basis of MDD led to the design and widespread use of selective serotonin reuptake inhibitors. However, given that only one-third of patients improve with SSRI it is reasonable to infer that the pathway involved is more complex than once hypothesized and there are more neurotransmitters, receptors, and molecules involved. The monoamine hypothesis does not explain why there is a delay in the onset of effect and action of SSRIs. Several studies have demonstrated that chronic stress is a risk factor for the development of MDD. Thus the monoamine hypothesis alone is not enough to fully account for the pathophysiology of MDD highlighting the need for further research involving the pathways of MDD. In this paper, we review the role of inflammation and cytokines on MDD and discuss other pathways involved in the development and persistence of depressive symptoms.

Serum Angiotensin-Converting Enzyme Methylation Level and Its Significance in Patients With Comorbid Major Depressive Disorder and Hypertension

OBJECTIVE

Major depressive disorder (MDD) often coexists with hypertension (HYT). DNA methylation has elicited vital functionality in their development. Angiotensin-converting enzyme (ACE) is a vital enzyme in blood pressure. This study investigated the effect of ACE methylation on depression and HYT severity in patients with comorbid MDD and HYT (MDD + HYT).

METHODS

A total of 119 patients (41 men, 78 women, average age: 56.8 ± 9.1 years) with MDD + HYT were enrolled, with 89 healthy subjects (29 men, 60 women, average age: 57.4 ± 9.7 years) were enrolled. The Hamilton Depression Rating Scale-17 and self-rating depression scale scoring scales were used to assess the depression degree of patients, serum ACE methylation level in MDD + HYT patients was measured by means of bisulfite sequencing polymerase chain reaction, with subsequent analysis of the diagnostic efficacy of ACE methylation for MDD + HYT. The independent risk factors for sMDD + HYT were explored.

RESULTS

Serum ACE methylation levels were significantly increased in MDD + HYT patients. The area under the curve of serum ACE methylation level for accurate diagnosis of MDD + HYT was 0.8471, and the cut-off value was 26.9 (sensitivity 83.19%, specificity 73.03%). ACE methylation was an independent risk factor for sMDD + HYT (P = 0.014; odds ratio, 1.071; 95% confidence interval = 1.014-1.131).

CONCLUSION

The elevated serum ACE methylation level (P < 0.001) in patients with MDD + HYT elicited definite diagnostic values for MDD + HYT, and ACE methylation level was independently correlated with sMDD + HYT (P < 0.05).

Lateral Habenula Beyond Avoidance: Roles in Stress, Memory, and Decision-Making With Implications for Psychiatric Disorders

In this Perspective review, we highlight some of the less explored aspects of lateral habenula (LHb) function in contextual memory, sleep, and behavioral flexibility. We provide evidence that LHb is well-situated to integrate different internal state and multimodal sensory information from memory-, stress-, motivational-, and reward-related circuits essential for both survival and decision making. We further discuss the impact of early life stress (ELS) on LHb function as an example of stress-induced hyperactivity and dysregulation of neuromodulatory systems within the LHb that promote anhedonia and motivational deficits following ELS. We acknowledge that recent technological advancements in manipulation and recording of neural circuits in simplified and well-controlled behavioral paradigms have been invaluable in our understanding of the critical role of LHb in motivation and emotional regulation as well as the involvement of LHb dysfunction in stress-induced psychopathology. However, we also argue that the use of ethologically-relevant behaviors with consideration of complex aspects of decision-making is warranted for future studies of LHb contributions in a wide range of psychiatric illnesses. We conclude this Perspective with some of the outstanding issues for the field to consider where a multi-systems approach is needed to investigate the complex nature of LHb circuitry interactions with environmental stimuli that predisposes psychiatric disorders.

Differential effects of an experimental model of prolonged sleep disturbance on inflammation in healthy females and males

Sleep disturbances, including disrupted sleep and short sleep duration, are highly prevalent and are prospectively associated with an increased risk for various widespread diseases, including cardiometabolic, neurodegenerative, chronic pain, and autoimmune diseases. Systemic inflammation, which has been observed in populations experiencing sleep disturbances, may mechanistically link disturbed sleep with increased disease risks. To determine whether sleep disturbances are causally responsible for the inflammatory changes reported in population-based studies, we developed a 19-day in-hospital experimental model of prolonged sleep disturbance inducing disrupted and shortened sleep. The model included delayed sleep onset, frequent nighttime awakenings, and advanced sleep offset, interspersed with intermittent nights of undisturbed sleep. This pattern aimed at providing an ecologically highly valid experimental model of the typical sleep disturbances often reported in the general and patient populations. Unexpectedly, the experimental sleep disturbance model reduced several of the assessed proinflammatory markers, namely interleukin(IL)-6 production by monocytes and plasma levels of IL-6 and C-reactive protein (CRP), presumably due to intermittent increases in the counterinflammatory hormone cortisol. Striking sex differences were observed with females presenting a reduction in proinflammatory markers and males showing a predominantly proinflammatory response and reductions of cortisol levels. Our findings indicate that sleep disturbances causally dysregulate inflammatory pathways, with opposing effects in females and males. These results have the potential to advance our mechanistic understanding of the pronounced sexual dimorphism in the many diseases for which sleep disturbances are a risk factor.

Transcriptome Profiling of Dysregulated GPCRs Reveals Overlapping Patterns across Psychiatric Disorders and Age-Disease Interactions

G-protein-coupled receptors (GPCRs) play an integral role in the neurobiology of psychiatric disorders. Almost all neurotransmitters involved in psychiatric disorders act through GPCRs, and GPCRs are the most common targets of therapeutic drugs currently used in the treatment of psychiatric disorders. However, the roles of GPCRs in the etiology and pathophysiology of psychiatric disorders are not fully understood. Using publically available datasets, we performed a comprehensive analysis of the transcriptomic signatures of G-protein-linked signaling across the major psychiatric disorders: autism spectrum disorder (ASD), schizophrenia (SCZ), bipolar disorder (BP), and major depressive disorder (MDD). We also used the BrainSpan transcriptomic dataset of the developing human brain to examine whether GPCRs that exhibit chronological age-associated expressions have a higher tendency to be dysregulated in psychiatric disorders than age-independent GPCRs. We found that most GPCR genes were differentially expressed in the four disorders and that the GPCR superfamily as a gene cluster was overrepresented in the four disorders. We also identified a greater amplitude of gene expression changes in GPCRs than other gene families in the four psychiatric disorders. Further, dysregulated GPCRs overlapped across the four psychiatric disorders, with SCZ exhibiting the highest overlap with the three other disorders. Finally, the results revealed a greater tendency of age-associated GPCRs to be dysregulated in ASD than random GPCRs. Our results substantiate the central role of GPCR signaling pathways in the etiology and pathophysiology of psychiatric disorders. Furthermore, our study suggests that common GPCRs’ signaling may mediate distinct phenotypic presentations across psychiatric disorders. Consequently, targeting these GPCRs could serve as a common therapeutic strategy to treat specific clinical symptoms across psychiatric disorders.

Preliminary Study on Changes of Sleep EEG Power and Plasma Melatonin in Male Patients With Major Depressive Disorder After 8 Weeks Treatment

Objective: To clarify the effects of escitalopram on sleep EEG power in patients with Major depressive disorder (MDD). Method: Polysomnography (PSG) was detected overnight, and blood samples were collected at 4 h intervals over 24 h from 13 male healthy controls and 13 male MDD patients before and after treatment with escitalopram for 8 weeks. The outcome measures included plasma melatonin levels, sleep architecture, and the sleep EEG power ratio. Results: Compared with healthy controls, MDD patients presented abnormalities in the diurnal rhythm of melatonin secretion, including peak phase delayed 3 h and a decrease in plasma melatonin levels at night and an increase at daytime, accompanied by sleep disturbances, a decrease in low-frequency bands and an increase in high-frequency bands, and the dominant right-side brain activity. Several of these abnormalities (abnormalities in the diurnal rhythm of melatonin secretion, partial sleep architecture parameters) persisted for at least the 8-week testing period. Conclusions: Eight weeks of treatment with escitalopram significantly improved subjective sleep perception and depressive symptoms of patients with MDD, and partially improved objective sleep parameters, while the improvement of circadian rhythm of melatonin was limited.

Impact of number of sleep ultradian cycles on polysomnographic parameters related to REM sleep in major depression: Implications for future sleep research in psychiatry

Given the contradictory data on REMS alterations in major depression, the aim of this study was to empirically demonstrate that based on the number of sleep ultradian cycles, it was possible to highlight different subtypes of major depression characterized by specific patterns of REMS alterations. Demographic and polysomnographic data from 211 individuals (30 healthy controls and 181 untreated major depressed individuals) recruited from the sleep laboratory database were analyzed. Major depressed individuals with sleep ultradian cycles <4 showed alterations consistent with REMS deficiency (non-shortened REM latency as well as decrease in REMS percentage, REMS duration and REMS/NREMS ratio) whereas major depressed individuals with sleep ultradian cycles >4 showed alterations consistent with REMS disinhibition (shortened REM latency as well as increase in REMS percentage, REMS duration and REMS/NREMS ratio). Regarding major depressed individuals with 4 sleep ultradian cycles, their REMS alterations were intermediate to those present in major depressed individuals with sleep ultradian cycles <4 and >4. Thus, in major depressed individuals, the highlighting of this heterogeneity of REMS alterations based on the number of sleep ultradian cycles seems to suggest the involvement of distinct pathophysiological mechanisms and could open new perspectives for future sleep research in psychiatry.

Alterations of neural network organisation during rapid eye movement sleep and slow-wave sleep in major depression: Implications for diagnosis, classification, and treatment

The aim of this study was to empirically investigate the network organisation during rapid eye movement sleep (REMS) and slow-wave sleep (SWS) using the effective connectivity measured using the Granger causality to identify new potential biomarkers for the diagnosis, classification, and potential favourable response to treatment in major depression. Polysomnographic data were analysed from 24 healthy individuals and 16 major depressed individuals recruited prospectively. To obtain the 19×19 connectivity matrix of all possible pairwise combinations of electrodes by the Granger causality method from our electroencephalographic data, we used the Toolbox MVGC multivariate Granger causality. The computation of network measures was realised by importing these connectivity matrices into the EEGNET Toolbox. Major depressed individuals (versus healthy individuals) and those with endogenous depression (versus those with neurotic depression) present alterations of small-world network organisation during REMS, whereas major depressed individuals with potential favourable response to electroconvulsive therapy (versus those with potential unfavourable response) have a less efficient small-world network organisation during SWS. Thus, alterations in network organisation during REMS could be biomarkers for the diagnosis and classification of major depressive episodes, whereas alterations of network organisation during SWS could be a biomarker to predict potential favourable response to treatment by electroconvulsive therapy.

Decreased serum potassium may disturb sleep homeostasis in essential hypertensives

The aim is to investigate the association between alterations in the serum potassium (K+) concentration and sleep architecture parameters in essential hypertensives. Two hundred ninety-two hypertensives undergoing polysomnography and providing blood samples were recruited. The sleep architecture was composed of sleep stages 1 (N1), 2 (N2), 3 (N3), 4 (N4) and REM. The light sleep stage (LST) was composed of N1 + N2, and the deep sleep stage (DST) was composed of N3 + N4. The potentialrelationships between electrolytes and sleep parameters were determined via univariate and multivariate analyses. The subjects were divided into two groups via the serum K⁺ median (3.86 mmol/L). The K⁺ < 3.86 mmol/L group showed significantly decreased N1 (7.10 ± 4.55% vs 8.61 ± 5.23%, p = 0.002), LST (71.48 ± 11.33% vs 75.92 ± 17.08%, p = 0.013), and periodic leg movement during sleep related to microarousals (MA) /arousal (PLMS-A) [4 (1~10) vs 8 (3~15)/night, p < 0.001] and increased REM (17.38 ± 6.43% vs 15.37 ± 6.18%, p = 0.007) compared to the K⁺ ≥ 3.86 mmol/L group. A subdivided analysis by gender showed that these changes were more statistically significant in men than in women. Significant positive correlations were identified between K⁺ and N1 (r = 0.169, p = 0^.004), as well as PLMS-A (r = 0.222, p < 0.001) in subjects. Compared to women, a significantly strong correlation was identified between K+ and REM sleep in men (r = 0.158, p = 0.028 vs. r = 0.078, p = 0.442). Multiple linear regression analysis indicated that K+ is significantly associated with N1 in all subjects (p = 0.03) and with REM in men (p = 0.008), even after adjusting for confounders. Decreased K+ may disturb the homeostasis of the sleep architecture, and gender may interfere with their links in the hypertensive population.

Evidence supporting a mechanistic role of sirtuins in mood and metabolic disorders

Sirtuins are NAD⁺-dependent histone deacetylases that play essential roles in cell survival, energy metabolism, inflammation, and aging; therefore, sirtuins are potential therapeutic targets in the treatment of type 2 diabetes, cancer, inflammatory and metabolic disorders, and neurodegenerative diseases. Available evidence provides the basis for hypothesizing that sirtuins 1, 2, and 3 (SIRT1, SIRT2, and SIRT3) may have a mechanistic role subserving mood disorders (i.e. downregulation) and associated co-morbidity (e.g. metabolic disorders). Specifically, the domains of general cognitive processes, as well as cognitive emotional processing may be particularly relevant to sirtuin physiology. Given the role of sirtuins in the perpetuation of circadian rhythmicity, and evidence of dysfunctional circadian cycling in mood disorders, sirtuins may be an underlying etiological factor that links circadian rhythm functionality with mood disorders. Caloric restriction, and caloric restriction mimetics (e.g. resveratrol) are all capable of upregulating sirtuin isoforms implicated in stress response syndromes. Repurposing existing treatments and/or discovery of novel agents capable of modulating sirtuin physiology may represent genuinely novel approaches for trans-diagnostic domains affected in mood disorders and other brain-based illnesses.

The Effects of Tai Chi on Sleep Quality in Chinese American Patients With Major Depressive Disorder: A Pilot Study

OBJECTIVE

This pilot study evaluated the effects of Tai Chi training on sleep quality (primary outcomes), and depression and social functioning levels (secondary outcomes) among patients with depression.

PARTICIPANTS

Sixteen depressed Chinese patients.

METHODS

Participants received 1-hr Tai Chi training sessions 2 times per week for 10 weeks. Patients' subjective sleep quality ratings, objective sleep quality measurements, and depression and social functioning levels were measured before, during, and after the intervention.

RESULTS

Sleep quality and depression outcomes improved significantly. Patients reported improved Pittsburgh Sleep Quality Index (PSQI) scores (9.6 ± 3.3 to 6.6 ± 5.2, p = 0.016), and cardiopulmonary coupling (CPC) analysis of electrocardiogram (ECG) showed decreased stable sleep onset latency (75.7 ± 100.6 to 20.9 ± 18.0, p = 0.014), increased stable sleep percentages (31.5 ± 18.7 to 46.3 ± 16.9, p = 0.016), and decreased unstable sleep percentages (45.3 ± 20.1 to 30.6 ± 16.5, p = 0.003). Patients also reported decreased Hamilton Rating Scale for Depression (HAM-D-17; 20.1 ± 3.7 to 7.8 ± 5.9, p < 0.001) and Beck Depression Inventory (BDI) scores (22.3 ± 9.1 to 11.1 ± 10.6, p = 0.006). Significant correlations were found between the changes in subjective sleep assessments ΔPSQI and ΔHAM-D-17 (r = 0.6, p = 0.014), and ΔPSQI and ΔBDI (r = 0.62, p = 0.010). Correlations between changes in objective sleep measurements and changes in depression symptoms were low and not significant.

CONCLUSIONS

Tai Chi training improved sleep quality and mood symptoms among depressed patients.

Predictors of Response to Ketamine in Treatment Resistant Major Depressive Disorder and Bipolar Disorder

Objectives: Extant evidence indicates that ketamine exerts rapid antidepressant effects in treatment-resistant depressive (TRD) symptoms as a part of major depressive disorder (MDD) and bipolar disorder (BD). The identification of depressed sub-populations that are more likely to benefit from ketamine treatment remains a priority. In keeping with this view, the present narrative review aims to identify the pretreatment predictors of response to ketamine in TRD as part of MDD and BD. Method: Electronic search engines PubMed/MEDLINE, ClinicalTrials.gov, and Scopus were searched for relevant articles from inception to January 2018. The search term ketamine was cross-referenced with the terms depression, major depressive disorder, bipolar disorder, predictors, and response and/or remission. Results: Multiple baseline pretreatment predictors of response were identified, including clinical (i.e., Body Mass Index (BMI), history of suicide, family history of alcohol use disorder), peripheral biochemistry (i.e., adiponectin levels, vitamin B12 levels), polysomnography (abnormalities in delta sleep ratio), neurochemistry (i.e., glutamine/glutamate ratio), neuroimaging (i.e., anterior cingulate cortex activity), genetic variation (i.e., Val66Met BDNF allele), and cognitive functioning (i.e., processing speed). High BMI and a positive family history of alcohol use disorder were the most replicated predictors. Conclusions: A pheno-biotype of depression more, or less likely, to benefit with ketamine treatment is far from complete. Notwithstanding, metabolic-inflammatory alterations are emerging as possible pretreatment response predictors of depressive symptom improvement, most notably being cognitive impairment. Sophisticated data-driven computational methods that are iterative and agnostic are more likely to provide actionable baseline pretreatment predictive information.

The management of fibromyalgia from a psychosomatic perspective: an overview

Fibromyalgia (FM) is a central sensitization syndrome characterized by chronic widespread pain. FM is often comorbid with psychiatric disorders, as well as psychological distress that worsens the quality-of-life of people affected. The aim was to collect current evidence about the management of FM from a psychosomatic perspective. The literature was synthesized and summarized in a narrative format. The literature search was carried out in PubMed; review articles, meta-analysis, overview, and guidelines published in the last 10 years written in English were included. Five main topics (Diagnostic criteria of FM; Pathogenesis of chronic widespread pain in FM; Early stress and trauma as predisposing factors for central sensitization; FM and Psychiatric comorbidity; Implications for treatment) were pointed out and discussed. Much evidence underlies the importance of considering and treating the comorbidity of FM with psychiatric disorders and psychological factors that affect pain management. Validation of FM as a central sensitization syndrome by a clinician facilitates therapeutic strategies that involve patients as active participants in the pain management process, likely leading to improved outcomes.

Sleep and Psychiatric Disorders in Persons With Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) frequently challenges the integrity of sleep function by affecting multiple brain areas implicated in controlling the switch between wakefulness and sleep and those involved in circadian and homeostatic processes; the malfunction of each causes a variety of disorders. In this review, we discuss recent data on the dynamics between disorders of sleep and mental/psychiatric disorders in persons with mTBI. This analysis sets the stage for understanding how a variety of physiological, emotional and environmental influences affect sleep and mental activities after injury to the brain. Consideration of the intricate links between sleep and mental functions in future research can increase understanding on the underlying mechanisms of sleep-related and psychiatric comorbidity in mTBI.

Depressive Symptoms Are Associated With Objectively Measured Sleep Parameters in Kidney Transplant Recipients

STUDY OBJECTIVES

Both depression and sleep complaints are very prevalent among kidney transplant (kTx) recipients. However, details of the complex relationship between sleep and depression in this population are not well documented. Thus, we investigated the association between depressive symptoms and sleep macrostructure parameters among prevalent kTx recipients.

METHODS

Ninety-five kTx recipients participated in the study (54 males, mean ± standard devation age 51 ± 13 years, body mass index 26 ± 4 kg/m2, estimated glomerular filtration rate 53 ± 19 ml/min/1.73 m2). Symptoms of depression were assessed by the Center for Epidemiologic Studies - Depression Scale (CES-D). After 1-night polysomnography each recording was visually scored and sleep macrostructure was analyzed.

RESULTS

The CES-D score was significantly associated with the amount of stage 2 sleep (r = 0.20, P < .05), rapid eye movement (REM) latency (r = 0.21, P < .05) and REM percentage (r = -0.24, P < .05), but not with the amount of slow wave sleep (r = -0.12, P > .05). In multivariable linear regression models the CES-D score was independently associated with the amount of stage 2 sleep (β: 0.205; confidence interval: 0.001-0.409; P = .05) and REM latency (β: 0.234; confidence interval: 0.001-0.468; P = .05) after adjustment for potential confounders.

CONCLUSIONS

Depressive symptoms among kTx recipients are associated with increased amount of stage 2 sleep and prolonged REM latency. Further studies are needed to confirm our findings and understand potential clinical implications.

Diet-Induced Obesity and Circadian Disruption of Feeding Behavior

Feeding behavior shows a rhythmic daily pattern, which in nocturnal rodents is observed mainly during the dark period. This rhythmicity is under the influence of the hypothalamic suprachiasmatic nucleus (SCN), the main biological clock. Nevertheless, various studies have shown that in rodent models of obesity, using high-energy diets, the general locomotor activity and feeding rhythms can be disrupted. Here, we review the data on the effects of diet-induced obesity (DIO) on locomotor activity and feeding patterns, as well as the effect on the brain sites within the neural circuitry involved in metabolic and rewarding feeding behavior. In general, DIO may alter locomotor activity by decreasing total activity. On the other hand, DIO largely alters eating patterns, producing increased overall ingestion and number of eating bouts that can extend to the resting period. Furthermore, within the hypothalamic areas, little effect has been reported on the molecular circadian mechanism in DIO animals with ad libitum hypercaloric diets and little or no data exist so far on its effects on the reward system areas. We further discuss the possibility of an uncoupling of metabolic and reward systems in DIO and highlight a gap of circadian and metabolic research that may help to better understand the implications of obesity.

Biological rhythms, metabolic syndrome and current depressive episode in a community sample

The purpose of this study was to assess the disruption in biological rhythms and metabolic syndrome (MetS) in individuals with depressive episode. This was a cross-sectional, population-based study with a representative sample of 905 young adults. Current depressive episode were confirmed by a psychologist using the Mini International Neuropsychiatric Interview (MINI)-Plus. Self-reported biological rhythms were assessed using the Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN). MetS was defined using modified NCEP/ATPIII criteria. Significant main effects of current depressive episode (p<0.001, η(2)=0.163) and MetS (p=0.001, η(2)=0.011) were observed on total BRIAN score. There was a significant interaction between depression and MetS in total biological rhythm scores (p=0.002, η(2)=0.011) as well as sleep (p=0.001, η(2)=0.016) and social domains (p<0.001, η(2)=0.014). In the depressive group, subjects with MetS had a higher disruption in total BRIAN scores (p=0.010), sleep domain (p=0.004), social domain (p=0.005) and in the eating pattern domain approached the level of significance (p=0.098), when compared to subjects with no MetS. The results of the present study showed that self-reported disruptions in biological rhythms are associated with key components of the MetS in community adults with MDD. The understanding of the complex interactions between biological rhythms, MetS and depression are important in the development of preventive and therapeutic strategies.

Nocturia: aetiology and treatment in adults

Nocturia is an extremely common condition that has major sequelae for affected patients. Through disruption of sleep, nocturia impairs quality of life and worsens health outcomes, and is associated with a variety of morbidities including diabetes, coronary artery disease, obstructive sleep apnoea, obesity, metabolic syndrome, and depression. Unsurprisingly, several studies have also linked nocturia with reduced survival. Nocturia is not simply a consequence of lower urinary tract disease; rather, it is a multifactorial disorder that is often a manifestation of an underlying renal or systemic disease. Through the use of the frequency volume chart, clinicians can accurately quantify nocturia and determine its aetiology. Evaluation of quality of life and sleep using simple measures is essential in order to assess the impact of nocturia on a patient. Numerous treatment options for nocturia exist, but most are associated with minor benefit or lack sufficient evidence supporting their use. By systematically analysing an individual's causes of nocturia, clinicians can design appropriate treatment strategies to most effectively treat this condition.

Polysomnographic correlates of inflammatory complement components in young healthy males

A growing body of evidence has delineated the predominant role of humoral mediators of inflammation in linking sleep with immunity. Nonetheless, characterization of the relationship between complement components with inflammatory functions and objective sleep measures has not been performed. In this study we investigated the relationships between objective measures of sleep and complement components with inflammatory functions. Thirty-six healthy male university students (age, 23.94±4.23 years; BMI, 23.44±2.67 kg/m(2)) completed the study. An RMS Quest 32 polysomnograph (PSG) was used for sleep recording. Non-fasting blood was collected before subjects went to bed on the second night in the sleep laboratory to estimate complement component 3 (C-3), complement component 4 (C-4), complement factor-H (Factor-H), C1-inhibitor (C1INH), complement factor I (CFI) and other inflammatory mediators, such as IL-6 and sICAM-1. Multiple linear regression analysis was used to assess the association between PSG sleep measures and inflammatory mediators. Higher values of C-3 and lower values of sICAM-1, C1INH, and CFI (adjusted model, R2=0.211, p<0.041) predicted longer sleep duration. Lower C-3 (adjusted model, R2=0.078, p<0.055) predicted higher N1 (%). Higher levels of C1INH and CFI and lower values of C-4 (model adjusted R2=0.269, p<0.008) predicted higher N3 (%). Higher C-3, higher C-4, lower IL-6, lower C1INH and lower CFI (model adjusted R2=0.296, p<0.007) predicted higher REM (%). Poor sleep measures were associated with increased levels of pro-inflammatory complement components and decreased anti-inflammatory complement components.

Prevalence of fibromyalgia and co-morbid bipolar disorder: A systematic review and meta-analysis

BACKGROUND

Fibromyalgia (FM) is a chronic disorder with high morbidity and significant health service utilization costs. Few studies have reported on the phenotypic overlap of FM and bipolar disorder (BD). The aim of this review is to qualitatively and quantitatively summarize the results and clinical implications of the extant literature on the co-occurrence of FM and BD.

METHODS

A systematic search of PubMed/Medline, Cochrane, PsycINFO, CINAHL and Embase was conducted to search for relevant articles. Articles were included if incidence and/or prevalence of BD was determined in the FM sample. Results of prevalence were pooled from all studies. Pooled odds ratio (OR) was calculated based on case-control studies using standard meta-analytic methods.

RESULTS

A total of nine studies were included. The pooled rate of BD comorbidity in samples of FM patients was 21% (n=678); however, results varied greatly as a function of study methodology. Case-controlled studies revealed a pooled OR of 7.55 of BD co-morbidity in samples of FM patients [95% Confidence Interval (CI)=3.9-14.62, FM n=268, controls n=413] with low heterogeneity (I(2)=0%).

LIMITATIONS

The current study was limited by the low number of available studies and heterogeneity of study methods and results.

CONCLUSIONS

These data strongly suggest an association between BD and FM. Future studies employing a validated diagnostic screen are needed in order to more accurately determine the prevalence of BD in FM. An adequate psychiatric assessment is recommended in FM patients with suspected symptoms consistent with BD prior to administration of antidepressants in the treatment of FM.

The link between depression and diabetes: the search for shared mechanisms

Depression is twice as common in people with type 1 or type 2 diabetes as in the general population, and is associated with poor outcomes. Evidence is growing that depression and type 2 diabetes share biological origins, particularly overactivation of innate immunity leading to a cytokine-mediated inflammatory response, and potentially through dysregulation of the hypothalamic-pituitary-adrenal axis. Throughout the life course, these pathways can lead to insulin resistance, cardiovascular disease, depression, increased risk of type 2 diabetes, and increased mortality. Proinflammatory cytokines might directly affect the brain, causing depressive symptoms. In type 1 diabetes, mediators of depression are not well studied, with research hindered by inconsistent definitions of depression and scarcity of observational, mechanistic, and interventional research along the life course. Despite few studies, evidence suggests that familial relationships and burden of a lifelong disorder with an onset early in personality development might contribute to increased vulnerability to depression. Overall, longitudinal research is needed to identify risk factors and mechanisms for depression in patients with diabetes, particularly early in the life course. Ultimately, improved understanding of shared origins of depression and diabetes could provide the potential to treat and improve outcomes of both disorders simultaneously. These shared origins are targets for primary prevention of type 2 diabetes.

Integrative neurobiology of metabolic diseases, neuroinflammation, and neurodegeneration

Alzheimer's disease (AD) is a complex, multifactorial disease with a number of leading mechanisms, including neuroinflammation, processing of amyloid precursor protein (APP) to amyloid β peptide, tau protein hyperphosphorylation, relocalization, and deposition. These mechanisms are propagated by obesity, the metabolic syndrome and type-2 diabetes mellitus. Stress, sedentariness, dietary overconsumption of saturated fat and refined sugars, and circadian derangements/disturbed sleep contribute to obesity and related metabolic diseases, but also accelerate age-related damage and senescence that all feed the risk of developing AD too. The complex and interacting mechanisms are not yet completely understood and will require further analysis. Instead of investigating AD as a mono- or oligocausal disease we should address the disease by understanding the multiple underlying mechanisms and how these interact. Future research therefore might concentrate on integrating these by “systems biology” approaches, but also to regard them from an evolutionary medicine point of view. The current review addresses several of these interacting mechanisms in animal models and compares them with clinical data giving an overview about our current knowledge and puts them into an integrated framework.

Early switching strategies in antidepressant non-responders: current evidence and future research directions

Studies have found that up to two-thirds of patients with major depressive disorder (MDD) do not fully respond to the first antidepressant. While switching antidepressants is a common strategy for antidepressant non-responders, there is still a lack of consensus about the optimal timing of a switch. Many clinicians wait for 6-12 weeks before considering a switch. The objectives of this paper are to (1) review the evidence for positive and negative predictive value (NPV) of early improvement at 2-4 weeks to predict final antidepressant response; (2) review randomized controlled trials (RCTs) that examine early switching strategies; and (3) provide future research directions and clinical recommendations for timing of antidepressant switching. We conducted a literature search for English-language studies via PubMed and Google Scholar, from 1984 to May 2013, with the following terms: 'antidepressants', 'MDD', 'time course', 'trajectory', 'early response', 'onset', 'delayed response', 'early improvement', 'predictors', 'switch', 'combination therapy', and 'augmentation'. Replicated evidence indicates that lack of early improvement (e.g. <20% reduction in a depression scale score) at 2-4 weeks can be an accurate predictor to identify eventual non-responders. The NPVs suggest that only about one in five patients with lack of improvement at 4 weeks will have a response by 8 weeks. Three RCTs examined early switch strategies, but results are inconsistent and comparisons limited by methodological differences. Future studies should incorporate a standard consensus definition of early improvement, discern whether the effect of early switching is specific to certain types of antidepressants, and determine whether early switch is superior to other strategies such as augmentation or combination. Notwithstanding these limitations, there is reasonable evidence to recommend earlier assessment for improvement. If there is no indication of early improvement at 2-4 weeks after starting an antidepressant, and taking into account other patient and clinical factors, a change in management can be considered.

Sleep loss as a factor to induce cellular and molecular inflammatory variations

A reduction in the amount of time spent sleeping occurs chronically in modern society. Clinical and experimental studies in humans and animal models have shown that immune function is impaired when sleep loss is experienced. Sleep loss exerts a strong regulatory influence on peripheral levels of inflammatory mediators of the immune response. An increasing number of research projects support the existence of reciprocal regulation between sleep and low-intensity inflammatory response. Recent studies show that sleep deficient humans and rodents exhibit a proinflammatory component; therefore, sleep loss is considered as a risk factor for developing cardiovascular, metabolic, and neurodegenerative diseases (e.g., diabetes, Alzheimer's disease, and multiple sclerosis). Circulating levels of proinflammatory mediators depend on the intensity and duration of the method employed to induce sleep loss. Recognizing the fact that the concentration of proinflammatory mediators is different between acute and chronic sleep-loss may expand the understanding of the relationship between sleep and the immune response. The aim of this review is to integrate data from recent published reports (2002-2013) on the effects of sleep loss on the immune response. This review may allow readers to have an integrated view of the mechanisms involved in central and peripheral deficits induced by sleep loss.