Comorbid sleep disorders in neuropsychiatric disorders across the life cycle.

The association between psychopathology and poor sleep has long been recognized. The current review focuses on the association between the most prevalent sleep disorders (insomnia, sleep-related breathing disorders and restless legs syndrome) and four major psychiatric disorders: alcohol dependence, schizophrenia, depression and anxiety disorders. Decreased total sleep time and increased sleep onset latency as measured by polysomnography as well an increase of the prevalence of insomnia has been reported in all of these psychiatric disorders. Furthermore, sleep disturbance is a risk factor for their development. Cognitive-behavioral therapy for insomnia has been shown to have a positive impact on both sleep and symptoms of depression and anxiety. Whether adequate treatment of sleep disorders can prevent the incidence of psychiatric disorders, remains to be investigated.

Insomnia-perchance a dream? Results from a NREM/REM sleep awakening study in good sleepers and patients with insomnia.

Study Objectives: Insomnia disorder (ID) is a frequent sleep disorder coupled with increased risks for somatic and mental illness. Although subjective complaints are severe, polysomnography (PSG) parameters show only modest differences between groups. Rapid eye movement (REM) sleep as the most aroused sleep state may be especially vulnerable to be perceived as wake. To directly assess possible differences, we determined auditory waking thresholds and sleep perception in patients with ID and healthy control participants (good sleeper controls [GSC]) in N2 and REM sleep. Methods: In case-control study, 27 patients with ID and 27 age- and gender-matched controls were included. Four consecutive nights were assessed in the sleep laboratory, with nights 3 and 4 each containing three awakenings either from stable N2 or REM sleep. Awakening thresholds in patients with ID did not differ from GSC, but decreased over the course of the night. Patients with ID indicated significantly more frequently than GSC having been awake when woken from REM sleep but not from N2 and were less sure when indicating they had been asleep. Additionally, participants with ID rated their REM sleep mentation as more emotionally negative compared with GSC. Conclusions: This study presents direct evidence that the subjective experience of insomnia might be specifically coupled to the REM sleep state. Assuming chronic hyperarousal as a central pathophysiologically relevant pathway for insomnia, this might become especially evident during REM sleep, thus reflecting a hybrid sleep state in insomnia being coupled with altered sleep perception.

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