Disturbances in hypothalamo pituitary adrenal and thyroid axis identify different sleep EEG patterns in major depressed patients

Association between the CLOCK gene polymorphism and depressive symptom mediated by sleep quality among non-clinical Chinese Han population

BACKGROUND

Depression is a common mental disorder associated with sleep problems and the circadian clock genes may underlie the relationship between the two in clinical samples. However, little is known about whether poor sleep quality is associated with depressive symptom in healthy individuals and whether is mediated by specific single-nucleotide polymorphisms (SNPs).

METHODS

Using a cross-sectional design, 444 university staff members were randomly recruited in Beijing. We used the Pittsburgh Sleep Quality Index (PSQI) to measure sleep quality, the Zung's Self-rating Depression Scale (SDS) to measure depressive symptom, and the Work Stress Scale to measure job stress. The CLOCK gene rs12649507 polymorphism was genotyped in 289 blood samples.

RESULTS

There were positive inter-correlations between job stress, PSQI and SDS (almost ps < 0.05). GG homozygotes of the SNP had higher PSQI and its sleep duration and daytime dysfunction scores than AA homozygotes (all Bonferroni corrected ps0.05). The SNP had no main effect on the SDS and did not interact with job stress to affect SDS, PSQI and its dimensions (all ps > 0.05). Interestingly, after controlling for job stress and covariates, the significant effect size of the SNP on the SDS mediated by the PSQI was 0.68 (95% CI [0.24, 1.35]).

LIMITATIONS

Some limitations included single professional background, cross-sectional study design, small sample size and potential confounding factors, which could be amended by future research.

CONCLUSIONS

Non-clinical Chinese carrying CLOCK gene rs12649507 G-allele may lead to poor sleep quality and further depression symptoms.

Hyperarousal during sleep in untreated, major depressed subjects with prodromal insomnia: A polysomnographic study

In primary insomnia, specific dynamics of hyperarousal are evident during the night. Similarly, in major depression, many elements also favor of the presence of hyperarousal. Thus, it would be interesting to investigate if hyperarousal presents the same dynamic in major depression. Polysomnographic data from 30 healthy controls, 66 patients with major depression and prodromal insomnia, and 86 primary insomnia sufferers recruited from the sleep laboratory database were studied for whole night and thirds of the night. Insomnia sufferers and patients with depression exhibit a similar polysomnographic pattern both for whole night (increased sleep latency and WASO and reduced SWS and REM) and thirds of night (increased WASO at first and last thirds, reduced SWS in first third, and reduced in REM in first and last third). No alterations were detected during the second third of the night. Just as in primary insomnia, the hyperarousal phenomenon is found mainly in major depression with prodromal insomnia during the sleep-onset period and the first and last thirds of the night, but lesser during the second third of the night. These specific dynamics of hyperarousal may aid in the understanding of the particular relationship between insomnia and depression.

Similar polysomnographic pattern in primary insomnia and major depression with objective insomnia: a sign of common pathophysiology?

BACKGROUND

Our aim is to verify empirically the existence of a major depressed subgroup with a similar polysomnographic pattern as primary insomnia, including at rapid eye movement sleep level.

METHODS

The polysomnographic data from 209 untreated individuals (30 normative, 84 primary insomnia sufferers, and 95 major depressed patients with objective insomnia) who were recruited retrospectively from the Erasme hospital database were studied for the whole night and thirds of the night.

RESULTS

Primary insomnia sufferers and major depressed patients with objective insomnia exhibit a similar polysomnographic pattern both for the whole night (excess of wake after sleep onset, deficit in slow-wave sleep/rapid eye movement sleep, and non-shortened rapid eye movement latency) and thirds of the night (excess of wake after sleep onset at first and last third, deficit in slow-wave sleep in first third, and deficit in rapid eye movement sleep in first and last third), including at rapid eye movement sleep level.

CONCLUSION

In our study, we demonstrated that major depressed patients with objective insomnia showed a similar polysomnographic pattern as primary insomnia, including at rapid eye movement sleep level, which supports the hypothesis of a common pathophysiology that could be hyperarousal. This opens new avenues for understanding the pathophysiology of major depression with objective insomnia.

Hyperarousal during sleep in untreated primary insomnia sufferers: A polysomnographic study

Because some evidence favors the hyperarousal model of insomnia, we sought to learn more about the dynamics of this phenomenon during sleep. Polysomnographic data from 30 normative subjects and 86 untreated primary insomnia sufferers recruited from the database of the sleep laboratory were studied for whole nights and in terms of thirds of the night. Untreated primary insomnia sufferers had an increased sleep latency and excess of WASO, together with a deficit in REM and NREM sleep during the entire night. In terms of thirds of the night, they presented a major excess of WASO during the first and last thirds of the night but an excess of lesser importance during the middle third. A deficit in SWS was found during the first third of the night, but for REM, the deficit was present during both the first and last thirds. Primary insomnia sufferers had no SWS or REM deficit during the second third of the night. We found that the hyperarousal phenomenon occurs mainly during the sleep-onset period of the first and last thirds of the night and is less important during the middle third. These results open new avenues for understanding the pathophysiology of primary insomnia.

Poor sleep predicts symptoms of depression and disability retirement due to depression

BACKGROUND

Disturbed sleep is associated with mood disorders. Both depression and insomnia may increase the risk of disability retirement. The longitudinal links among insomnia, depression and work incapacity are poorly known.

METHODS

We examined association of self-reported sleep quality with incident symptoms of depression and disability retirement due to depressive disorders in a longitudinal population-based sample of twins (n=12,063 individuals). These adults were categorized by their sleep quality in 1975 and 1981, excluding individuals with depressed mood in 1975/1981. The outcomes were the Beck Depression Inventory (BDItot) and its subscale Negative Attitudes Towards Self (BDINATS) in 1990 as dichotomized measures, and the incidence of disability retirement due to depressive disorder during 1991-2004.

RESULTS

Onset of poor sleep between 1975 and 1981 predicted incident depression (BDItot OR=4.5, 95% CI: 2.7-7.4, BDINATS OR=2.0, 95% CI: 1.4-2.7), while persistent poor sleep showed somewhat weaker effects (BDItot; OR=2.5, 95% CI: 1.0-6.0, BDINATS OR=1.9, 95% CI: 1.1-3.3). Among those with few recent stressful life events, onset of poor sleep predicted strongly depression (BDINATS OR=9.5, 95% CI: 3.7-24.2). Likewise onset of poor sleep by 1981 increased the risk of disability retirement due to depression (OR=2.9, 95% CI: 1.8-4.9) with a similar risk among those with persistent poor sleep (OR=2.7, 95% CI: 1.3-5.7).

LIMITATIONS

Lack of baseline diagnostic interviews; sleep quality based on self-report.

CONCLUSIONS

Poor sleep is of importance in etiology of depression and disability retirement due to depression. This emphasizes the importance of early detection and treatment of sleep disturbances.

Alterations in hypothalamic-pituitary-adrenal/thyroid (HPA/HPT) axes correlated with the clinical manifestations of depression

The alterations of hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-thyroid (HPT) axes are important neuroendocrine abnormalities in depression. We aimed to identify some potential associations between these alterations and the clinical manifestations of depression in a sample of Chinese origin. 565 depressed patients of Chinese Han region were collected and seven kinds of hormones in HPA and HPT axes were detected. A 17-item Hamilton Depression Rating Scale (HAMD-17) and a 14-item Hamilton Anxiety Rating Scale (HAMA-14) were used to evaluate the baseline condition of each patient. 519 patients were enrolled into analysis. The patients with dysfunction of HPA axis had susceptibility to agitation symptoms (HAMD9 item) and cognitive disorders (HAMD2, 3 and 9 items), while those with normal function of HPA axis had susceptibility to shallow sleep (HAMD5 item). The patients with dysfunction of HPT axis had susceptibility to difficulty in falling asleep (HAMD4 item), weight loss (HAMD16 item) and gastrointestinal symptoms (HAMD12 item). Besides, the patients with dysfunctions of both HPA and HPT axes showed remarkable retardation symptoms (HAMD8 item). These findings might provide some evidences for the clinical subgrouping and management individualization of depressed patients according to the neuroendocrine alterations.

R278995/CRA0450, a corticotropin-releasing factor (CRF(1)) receptor antagonist modulates REM sleep measures in rats: Implication for therapeutic indication

Abnormalities in the regulation of the hypothalamic stress hormone corticotropin-releasing factor (CRF) are thought to play a critical role in mood disorders. Consequently, CRF receptor antagonists have been proposed as potential novel therapeutic agents of these conditions. Sleep disturbance is common in depressed patients and changed sleep-wake architecture is considered as potential predictor or surrogate marker of response to treatment. The aim of our study was to characterise the effects of oral administration of the corticotropin-releasing factor CRF(1) receptor antagonist R278995/CRA0450 (3 and 10mg/kg) on sleep-wake organization and electroencephalographic (EEG) components in Sprague-Dawley rats, and to determine whether the changes observed in the sleep-EEG pattern resemble those seen with antidepressants. At 3mg/kg, R278995/CRA0450 produced minor changes in sleep behaviour, while an overall reduction in power spectra was observed during deep slow wave sleep. At 10mg/kg, R278995/CRA0450 consistently reduced rapid eye movement (REM) sleep (-75.4%) and increased the REM sleep onset latency (+67%, 92.1±4.9min for vehicle vs. 153.8±24min for R278995/CRA0450), in the absence of systematic changes in spectral EEG pattern, which are characteristic anti-depressant-like effects. These findings in rats indicate that the corticotropin-releasing factor CRF(1) receptor antagonist R278995/CRA0450 is centrally active under standard conditions as it inhibits REM sleep and promotes wakefulness. The characteristic changes found in the sleep EEG model further support the hypothesis that R278995/CRA0450 could exert a non-sedative, antidepressant-like action.

A meta-analysis of electroencephalographic sleep in depression: evidence for genetic biomarkers

BACKGROUND

Research on whether any electroencephalographic (EEG) sleep abnormalities observed among individuals with major depressive disorder (MDD) represent genetic biomarkers remains inconclusive. We aimed to identify EEG-based biomarkers of MDD through a review of studies from three populations: individuals with MDD, individuals with MDD under remission, and never depressed high-risk probands (HRPs) of individuals with MDD.

METHODS

We searched databases such as MEDLINE and PsycINFO for EEG studies published since 1970. Of the 886 records, our selection criteria identified 56 studies that employed standardized EEG scoring procedures and addressed confounds such as participant reactivity and drug effects. We then used fixed-effects models to calculate average weighted mean differences in EEG parameters between clinical groups across these studies.

RESULTS

Individuals with MDD differed significantly from control subjects on several EEG variables. However, remitted individuals showed normalization of all affected EEG parameters except rapid eye movement (REM) density and slow-wave sleep (SWS). Surprisingly, proportion of SWS was significantly shorter during remission than depression. Never-depressed HRPs also exhibited significantly elevated REM density and reduced SWS. Finally, these parameters constituted the only two EEG variables that were not moderated by depression severity.

CONCLUSIONS

Individuals experiencing MDD and those in remission exhibit increased REM density and shortened SWS, as do HRPs with no history of MDD. Thus, this combination of EEG features may represent a genetic biomarker of MDD. Further, SWS appears to be shorter during remission than depression, suggesting its role as both a genetic marker as well as a biological scar of the disorder.

Comorbidity of insomnia and depression

During the last decade, several studies have shown that insomnia, rather than a symptom of depression, could be a medical condition on its own, showing high comorbidity with depression. Epidemiological research indicates that insomnia could lead to depression and/or that common causalities underlie the two disorders. Neurobiological and sleep EEG studies suggest that a heightened level of arousal may play a common role in both conditions and that signs of REM sleep disinhibition may appear in individuals prone to depression. The effects of antidepressant drugs on non-REM and REM sleep are discussed in relation to their use in insomnia comorbid with depression. Empirical treatment approaches are behavioral management of sleep combined with prescription of a sedative antidepressant alone, co-prescription of two antidepressants, or of an antidepressant with a hypnotic drug.

Effects of sleep restriction periods on serum cortisol levels in healthy men

OBJECTIVES

To clarify effects of partial sleep deprivation (SD) on morning (07:00) serum cortisol concentrations in two protocols that restricted sleep to 3h/day in healthy adult men. The study was also designed to delineate the relationship between anxiety levels in the morning and slow wave sleep (SWS) periods at night.

METHODS

Ten young adult Han Chinese males were recruited to participate in an 'earlier-night' sleep restriction (SR) period (sleep from 00:00 to 03:00) and then a 'later-night' SR period (sleep from 03:00 to 06:00). The duration of each SR period was 4 days, followed by a recovery night. The SR periods were separated by 10 days of normal sleep. Blood samples of serum cortisol were drawn at 07:00 during each of two SR periods for six consecutive mornings (for a total of 12 measurements per subject), and anxiety levels were also assessed over the same period by the State portion of the State-Trait Anxiety Inventory (STAI). Sleeping processes were monitored by polysomnogram.

RESULTS

Serum cortisol levels decreased after SR (P<0.05) in both paradigms, with greater decreases evident after later-night sleep loss than after earlier-night sleep loss. Cortisol levels were significantly, negatively correlated to the number of days of earlier-night SR, but not to later-night SR. Anxiety scores increased gradually in both conditions. The time of SWS changed indiscriminately in both paradigms. Cortisol levels returned to baseline after one night of recovery sleep.

CONCLUSIONS

Cortisol decreased in both SR conditions, especially in the earlier-night SR protocol, even though SWS time and anxiety levels changed roughly in the same manner in both conditions. Data suggested that sleep loss at different times of the night affects the hypothalamic-pituitary-adrenal axis (HPA-axis) differentially.

Brain-immune interactions and disease susceptibility

Many studies have established the routes by which the immune and central nervous (CNS) systems communicate. This network of connections permits the CNS to regulate the immune system through both neuroendocrine and neuronal pathways. In turn, the immune system signals the CNS through neuronal and humoral routes, via immune mediators and cytokines. This regulatory system between the immune system and CNS plays an important role in susceptibility and resistance to autoimmune, inflammatory, infectious and allergic diseases. This review focuses on the regulation of the immune system via the neuroendocrine system, and underlines the link between neuroendocrine dysregulation and development of major depressive disorders, autoimmune diseases and osteoporosis.

Effects of electroconvulsive therapy on the thyrotropin-releasing hormone test in patients with depression

We investigated the acute and lasting effects of electroconvulsive therapy (ECT) on the thyroid-stimulating hormone (TSH) response to thyrotropin-releasing hormone (TRH) in patients with depression. The TRH stimulation test was conducted (1) under basal conditions, after a first ECT, and at the end of a therapeutic course of 7 ECTs in 20 inpatients with depression; (2) before the initiation of antidepressant therapy and after the therapeutic response in 16 other inpatients with depression who responded to antidepressant drug treatment; and (3) in 20 healthy control subjects. Baseline TSH levels were lower in patients with depression, especially in those with more severe depression who were considered appropriate for ECT. Before the treatment, TSH response to TRH did not differ between the patients with depression and controls; however, more blunted TSH responses to TRH were observed in these patients compared with the controls. TSH response to TRH changed neither with one ECT nor throughout consecutive ECT sessions in patients with depression. Drug treatment also was found to have no impact on this response. These findings suggest that the therapeutic action of ECT in depression is not directly related to its effects on the hypothalamic-pituitary-thyroid axis. However, possible delayed effects of ECT on the HPT axis function should not be overlooked.

Sleep microstructure around sleep onset differentiates major depressive insomnia from primary insomnia

In the present study we investigate whether alterations of sleep propensity or of wake propensity are implicated in sleep initiation disturbances encountered in major depressive insomnia and in primary insomnia. For this purpose, the time course of electroencephalogram (EEG) power density during the period preceding sleep onset and during the first non-rapid eye movement (REM) period was examined in three age and gender matched groups of 10 women and 11 men (healthy controls, primary insomniacs and depressive insomniacs). In contrast to healthy controls and depressive insomniacs, patients with primary insomnia did not experience a gradual decrease of their alpha and beta1 power during the sleep onset period and had a lower delta activity in the 5 min preceding sleep onset. Compared with the two other groups, depressive patients exhibit less dynamic changes in slow wave activity during the first non-REM period. The present results suggest that hyperarousal (high 'Process W') may mainly be implicated in the sleep initiation difficulties of primary insomniacs whereas the homeostatic sleep regulation process seems to be partially maintained. In our major depressed patients, the sleep initiation disturbances appeared to relate to a lower sleep pressure (low 'Process S') rather than to hyperarousal. This study supports the idea that different mechanisms are implicated in sleep disturbances experienced by primary insomniacs and major depressive insomniacs.

Effects of antidepressant treatment on thyrotropin-releasing hormone stimulation, growth hormone response to L-DOPA, and dexamethasone suppression tests in major depressive patients

Dexamethasone suppression (DST), thyroid-stimulating hormone (TSH) and prolactin (PRL) responses to thyrotropin-releasing hormone (TRH) and growth hormone (GH) response to L-DOPA tests were evaluated in 19 depressed inpatients before the commencement of the antidepressant treatment and after the clinical response to examine: (i) the functional relationships among the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-thyroid (HPT) axis and dopaminergic system in depression, (ii) any alterations in these hormonal functions with the antidepressant treatment. TSH responses to TRH showed a tendency to increase from pre- to posttreatment period, while TRH-induced PRL and L-DOPA-induced GH responses did not change with treatment in depressed patients who responded to the treatment. Females showed significantly higher TSH and PRL responses to TRH compared to males. No interconnections were found among the responses in DST, TRH stimulation test and L-DOPA-induced GH test in the patients. The results do not support the interrelations between the abnormalities in the HPT and HPA axes and central dopaminergic activity in depression.