Since ancient times it is known that melancholia and sleep disturbances co-occur. The introduction of polysomnography into psychiatric research confirmed a disturbance of sleep continuity in patients ...with depression, revealing not only a decrease in Slow Wave Sleep, but also a disinhibition of REM (rapid eye movement) sleep, demonstrated as a shortening of REM latency, an increase of REM density, as well as total REM sleep time. Initial hopes that these abnormalities of REM sleep may serve as differential-diagnostic markers for subtypes of depression were not fulfilled. Almost all antidepressant agents suppress REM sleep and a time-and-dose-response relationship between total REM sleep suppression and therapeutic response to treatment seemed apparent. The so-called Cholinergic REM Induction Test revealed that REM sleep abnormalities can be mimicked by administration of cholinomimetic agents. Another important research avenue is the study of chrono-medical timing of sleep deprivation and light exposure for their positive effects on mood in depression. Present day research takes the view on insomnia, i.e., prolonged sleep latency, problems to maintain sleep, and early morning awakening, as a transdiagnostic symptom for many mental disorders, being most closely related to depression. Studying insomnia from different angles as a transdiagnostic phenotype has opened many new perspectives for research into mechanisms but also for clinical practice. Thus, the question is: can the early and adequate treatment of insomnia prevent depression? This article will link current understanding about sleep regulatory mechanisms with knowledge about changes in physiology due to depression. The review aims to draw the attention to current and future strategies in research and clinical practice to the benefits of sleep and depression therapeutics.
Summary Chronic insomnia is defined by difficulties in falling asleep, maintaining sleep, and early morning awakening, and is coupled with daytime consequences such as fatigue, attention deficits, ...and mood instability. These symptoms persist over a period of at least 3 months (Diagnostic and Statistical Manual 5 criteria). Chronic insomnia can be a symptom of many medical, neurological, and mental disorders. As a disorder, it incurs substantial health-care and occupational costs, and poses substantial risks for the development of cardiovascular and mental disorders, including cognitive deficits. Family and twin studies confirm that chronic insomnia can have a genetic component (heritability coefficients between 42% and 57%), whereas the investigation of autonomous and central nervous system parameters has identified hyperarousal as a final common pathway of the pathophysiology, implicating an imbalance of sleep–wake regulation consisting of either overactivity of the arousal systems, hypoactivity of the sleep-inducing systems, or both. Insomnia treatments include benzodiazepines, benzodiazepine-receptor agonists, and cognitive behavioural therapy. Treatments currently under investigation include transcranial magnetic or electrical brain stimulation, and novel methods to deliver psychological interventions.
Previous research has identified insomnia as a predictor for the onset of depression. The aim of this meta-analysis is to investigate whether insomnia also predicts the onset of other mental ...disorders. Longitudinal studies were eligible for inclusion if they investigated insomnia at baseline (including nighttime- and daytime-symptoms) as a predictor of the later onset of psychopathology within a follow-up time-frame of at least 12 mo. Thirteen primary studies were included. The results suggest that insomnia is a significant predictor for the onset of depression (10 studies, OR 2.83, CI 1.55–5.17), anxiety (six studies, OR 3.23, CI 1.52–6.85), alcohol abuse (two studies, OR 1.35, CI 1.08–1.67, and psychosis (one study, OR 1.28, CI 1.03–1.59). The overall risk of bias in the primary studies was moderate. This meta-analysis provides evidence that insomnia increases the risk for psychopathology. A future research agenda should include more prospective studies using established diagnostic criteria, assessing insomnia at baseline and including long-term follow-up intervals evaluating a wider range of mental disorders. In addition, prospective long-term interventional studies investigating the efficacy of insomnia treatment for the prevention of mental disorders are called for.
Abstract Background In many patients with depression, symptoms of insomnia herald the onset of the disorder and may persist into remission or recovery, even after adequate treatment. Several studies ...have raised the question whether insomniac symptoms may constitute an independent clinical predictor of depression. This meta-analysis is aimed at evaluating quantitatively if insomnia constitutes a predictor of depression. Methods PubMed, Medline, PsycInfo, and PsycArticles databases were searched from 1980 until 2010 to identify longitudinal epidemiological studies simultaneously investigating insomniac complaints and depressed psychopathology. Effects were summarized using the logarithms of the odds ratios for insomnia at baseline to predict depression at follow-up. Studies were pooled with both fixed- and random-effects meta-analytic models in order to evaluate the concordance. Heterogeneity test and sensitivity analysis were computed. Results Twenty-one studies met inclusion criteria. Considering all studies together, heterogeneity was found. The random-effects model showed an overall odds ratio for insomnia to predict depression of 2.60 (confidence interval CI: 1.98–3.42). When the analysis was adjusted for outliers, the studies were not longer heterogeneous. The fixed-effects model showed an overall odds ratio of 2.10 (CI: 1.86–2.38). Limitations The main limit is that included studies did not always consider the role of other intervening variables. Conclusions Non-depressed people with insomnia have a twofold risk to develop depression, compared to people with no sleep difficulties. Thus, early treatment programs for insomnia might reduce the risk for developing depression in the general population and be considered a helpful general preventive strategy in the area of mental health care.
Summary Primary insomnia is defined as difficulties in falling asleep, maintaining sleep or non-restorative sleep accompanied by significantly impaired daytime functioning in the absence of a ...specific physical, mental or substance-related cause. The current review provides substantial support for the concept that hyperarousal processes from the molecular to the higher system level play a key role in the pathophysiology of primary insomnia. Autonomous, neuroendocrine, neuroimmunological, electrophysiological and neuroimaging studies demonstrate increased levels of arousal in primary insomnia during both night and daytime. In the light of neurobiological theories of sleep–wake regulation, primary insomnia may be conceptualized as a final common pathway resulting from the interplay between a genetic vulnerability for an imbalance between arousing and sleep-inducing brain activity, psychosocial/medical stressors and perpetuating mechanisms including dysfunctional sleep-related behavior, learned sleep preventing associations and other cognitive factors like tendency to worry/ruminate.
SUMMARY The present review provides an assessment of the efficacy and safety of benzodiazepine receptor agonists (BZRAs) and psychological and behavioral interventions for insomnia. These methods ...include relaxation techniques, sleep hygiene rules, stimulus control, sleep restriction and cognitive techniques, often also referred to as cognitive-behavioral therapy (CBT) when encompassing cognitive strategies and at least one kind of behavioral intervention. In order to provide a comprehensive assessment of the literature regarding the efficacy and safety of these standard treatments for insomnia, an integrative synthesis of the existing meta-analytic studies for each of the various treatment modalities was conducted. Where meta-analytic studies were not available, data from double-blind placebo-controlled randomized controlled trials (RCTs) were included. The summary findings from this review are (1) BZRAs and psychological and behavioral methods are effective to treat insomnia in the short-term and the latter have significantly more durable effects when active treatment is discontinued; and (2) there is only very limited evidence that BZRAs retain their efficacy during long-term treatment. The present review underscores the need for further research regarding the comparative efficacy and safety of these treatments for insomnia, how this varies with age and comorbidity, and how the various treatment modalities impact (1) daytime functioning, (2) quality of life, (3) health care utilization; and (4) pharmacoeconomics. Finally, it is particularly important that studies be conducted to determine if successful insomnia treatment influences the clinical course of the diseases that often occur co-morbidly with sleep continuity disturbance.
Summary Insomnia is a highly prevalent health problem worldwide. Primary insomnia (PI), i.e., insomnia not due to another disorder or substance use, represents a model to elucidate the ...pathophysiology of sleep. However, prior research in patients with PI has failed to demonstrate consistent abnormalities in the state-of-the-art assessment of sleep (polysomnography). The aim of this meta-analysis was to clarify whether there are identifiable polysomnographic sleep changes that correspond to the subjective complaints of patients with PI. Medline and PsycInfo databases were searched from 1994 to 2012. Effects were calculated as standardized mean differences. Studies were pooled with the random-effects meta-analytic model. Twenty-three studies met inclusion criteria. In total, 582 patients with PI and 485 good sleeper controls (GSC) were evaluated. The results showed that patients with PI present a disruption of sleep continuity and a significant reduction of slow wave sleep (SWS) and rapid eye movement (REM) sleep compared to GSC. The observed changes in sleep architecture, i.e., reductions in SWS and REM sleep, hitherto did not count among the typical polysomnographic findings in patients with PI. An advanced knowledge of the polysomnographic changes in PI may add to foster the understanding of the pathophysiology of sleep and its bi-directional relationships with somatic and mental disorders.
The link between co-morbid insomnia and depression has been demonstrated in numerous groups. Insomnia has been associated with: (1) an increased risk of developing subsequent depression; (2) an ...increased duration of established depression; and (3) relapse following treatment for depression. In addition, specific insomnia symptoms, such as nocturnal awakening with difficulty resuming sleep, are more strongly associated with depression than classic symptoms of insomnia. Participants of a workshop, held at the 6th annual meeting of The International Sleep Disorders Forum: The Art of Good Sleep in 2008, evaluated whether the effective management of sleep disorders could reduce both concurrent depressive symptoms and the risk of developing subsequent depression. Following the workshop, a targeted literature review was conducted. Initial evidence demonstrated that in patients with insomnia and co-morbid depression either pharmacological treatment of insomnia or psychological treatment in the form of cognitive behavioural therapy for insomnia improved both insomnia and depressive symptoms. Although these appeared to be promising treatment strategies, however, of the 27 identified treatment studies, only one large well-designed randomized controlled trial comparing the efficacy of eszopiclone plus fluoxetine with placebo plus fluoxetine demonstrated unequivocal evidence that improvements in insomnia symptoms conferred additive benefits on depressive outcomes. In addition, it was unclear whether any differences exist in efficacy between sedating versus non-sedating pharmacotherapies for insomnia in this patient group. Further studies of sufficient sample size and duration are needed to evaluate combinations of pharmacological (either sedating or non-sedating) and psychological interventions in co-morbid insomnia and depression. This article reviews the level of evidence, recommendations and areas of particular interest for further study and discussion arising from this workshop.
Insomnia has been found to be a clinical predictor of subsequent depression. Nevertheless the biological processes underlying this causal relationship are yet not fully understood. Both conditions ...share a common imbalance of the arousal system. Patients with insomnia present fragmented REM sleep, which probably interferes with basal processes of emotion regulation. The interaction between the arousal and the affective system with the persistence of the disorder could slowly alter also the cognitive system and lead to depression. Although preliminary results seem to support this hypothesis, data are still too few to make valid conclusions.
Highlights • Sleep loss is common during pregnancy. It may account for its adverse outcomes. • Common pathophysiological mechanisms are related to stress system activation. • Sleep loss may lead to ...stress “overload” contributing to adverse pregnancy outcomes. • Sleep loss during pregnancy can be regarded as a stress results and as a stressor per se.
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