Sleep electroencephalographic abnormalities in adolescent depressives: effects of scopolamine

Peripheral and neural correlates of self-harm in children and adolescents: a scoping review

BACKGROUND

Self-harm in children and adolescents is difficult to treat. Peripheral and neural correlates of self-harm could lead to biomarkers to guide precision care. We therefore conducted a scoping review of research on peripheral and neural correlates of self-harm in this age group.

METHODS

PubMed and Embase databases were searched from January 1980-May 2020, seeking English language peer-reviewed studies about peripheral and neural correlates of self-harm, defined as completed suicide, suicide attempts, suicidal ideation, or non-suicidal self-injury (NSSI) in subjects, birth to 19 years of age. Studies were excluded if only investigating self-harm in persons with intellectual or developmental disability syndromes. A blinded multi-stage assessment process by pairs of co-authors selected final studies for review. Risk of bias estimates were done on final studies.

RESULTS

We screened 5537 unduplicated abstracts, leading to the identification of 79 eligible studies in 76 papers. Of these, 48 investigated peripheral correlates and 31 examined neural correlates. Suicidality was the focus in 2/3 of the studies, with NSSI and any type of self-harm (subjects recruited with suicidality, NSSI, or both) investigated in the remaining studies. All studies used observational designs (primarily case-control), most used convenience samples of adolescent patients which were predominately female and half of which were recruited based on a disorder. Over a quarter of the specific correlates were investigated with only one study. Inter-study agreement on findings from specific correlates with more than one study was often low. Estimates of Good for risk of bias were assigned to 37% of the studies and the majority were rated as Fair.

CONCLUSIONS

Research on peripheral and neural correlates of self-harm is not sufficiently mature to identify potential biomarkers. Conflicting findings were reported for many of the correlates studied. Methodological problems may have produced biased findings and results are mainly generalizable to patients and girls. We provide recommendations to improve future peripheral and neural correlate research in children and adolescents, ages 3-19 years, with self-harm.

Sleep architecture and emotional inhibition processing in adolescents hospitalized during a suicidal crisis

BACKGROUND

Suicide is the second leading cause of death in adolescents. Sleep disturbances could alter inhibitory processes and contribute to dangerous behaviors in this critical developmental period. Adolescents in suicidal crisis have been shown to have lighter sleep compared to healthy controls. Additionally, suicidal adolescents have lower neural resources mobilized by emotionally charged inhibition processing. The present exploratory study aimed to determine how sleep architecture in suicidal adolescents may relate to inhibition processing in response to emotional stimuli.

METHODS

Ten adolescents between 12 and 17 years of age with a diagnosis of major depressive disorder and who attempted suicide were recruited while hospitalized for a suicidal crisis in a psychiatric inpatient unit. Event-related potentials (ERPs) were recorded prior to bedtime during a Go/NoGo task involving pictures of sad, happy, and neutral faces. Polysomnography was then recorded throughout the night. Pearson correlations were conducted to investigate how inhibition performance and ERP parameters reflecting inhibition processing (i.e., P3d and N2d derived from difference waveform calculated as NoGo minus Go trials) relate to sleep architecture.

RESULTS

Poorer inhibition accuracy in response to emotional stimuli was significantly correlated with shorter REM sleep latency, higher REM sleep, and more frequent nocturnal awakenings. The P3d in response to sad faces was negatively correlated with NREM2 sleep and positively correlated with NREM3 sleep. No such association with the P3d was found for happy or neutral stimuli. There were no significant correlations for the N2d.

CONCLUSION

Altered sleep in adolescents with depression who are in a suicidal crisisis associated with behavioral inhibition difficulties and fewer neural resources mobilized by inhibitory processes in emotionally charged contexts. This highlights the importance of addressing sleep disturbances while managing suicidal crises in adolescents.

Snoring Remediation with Oral Appliance Therapy Potentially Reverses Cognitive Impairment: An Intervention Controlled Pilot Study

Respiration rate (RR) dynamics entrains brain neural networks. RR differences between mild cognitive impairment (MCI) and Alzheimer’s disease (AD) in response to oral appliance therapy (OAT) are unknown. This pilot study investigated if RR during stable sleep shows a relationship to pathological severity in subjects with MCI and AD who snore and if RR is influenced following stabilization of the upper airway using OAT. The study cohort was as follows: cognitively normal (CN; n = 14), MCI (n = 14) and AD (n = 9); and a sub-population receiving intervention, CN (n = 5), MCI (n = 7), AD (n = 6) subjects. The intervention used was an oral appliance plus a mouth shield (Tx). RR maximum (max) rate (breaths/minute) and RR fluctuation during 2116 stable sleep periods were measured. The Montreal cognitive assessment (MoCA) was administered before and after 4 weeks with Tx. Baseline data showed significantly higher RR fluctuation in CN vs. AD (p < 0.001) but not between CN vs. MCI (p = 0.668). Linear mixed model analysis indicated Tx effect (p = 0.008) for RR max. Tx after 4 weeks lowered the RR-max in MCI (p = 0.022) and AD (p < 0.001). Compared with AD RR max, CN (p < 0.001) and MCI (p < 0.001) were higher with Tx after 4 weeks. Some MCI and AD subjects improved executive and memory function after 4 weeks of Tx.

Do insomnia and/or sleep disturbances predict the onset, relapse or worsening of depression in community and clinical samples of children and youth? Protocol for a systematic review and meta-analysis

INTRODUCTION

Disturbed sleep represents a potentially important modifiable risk factor for the development of depression in children and youth. This protocol for a systematic review proposes to investigate whether insomnia and/or sleep disturbances predict child and youth depression in community and clinical-based samples.

METHODS AND ANALYSIS

The protocol adheres to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines. English-written, longitudinal studies that quantitatively estimated the prediction of depression by insomnia and/or sleep disturbances in individuals 5-24 years of age will be included. EMBASE, MEDLINE, PsychINFO, Scopus and Web of Science and grey literature will be searched from 1980 to the present. For the selection of studies, two reviewers will be involved. Data extraction will be conducted by one author and checked independently by a second author. Risk of bias will be appraised using the Research Triangle Institute Item Bank tool. Heterogeneity will be measured using the I2 statistics. Meta-analysis will be carried out if ≥3 results are available and if outcome measures can be pooled. The choice between a random-effect or fixed-effect model will be based both on the I2 statistics and the participant and study characteristics of the combined studies. Results of the meta-analyses will be summarised by a forest plot. Analyses will be performed in subgroups stratified by key variables defined depending on the amount and type of information retrieved.A narrative synthesis will be conducted in place of the meta-analysis should the pooling of data not be possible. Quality of evidence will be rated using the Grading of Recommendations Assessment, Development and Evaluation guidelines.As this is a protocol for systematic review and meta-analysis of published data, ethics review and approval are not required. The findings will be published in a peer-reviewed journal and disseminated at scientific conferences and in patient advocacy organisations.

PROSPERO REGISTRATION NUMBER

CRD42019136729.

Sleep architecture in adolescents hospitalized during a suicidal crisis

OBJECTIVE/BACKGROUND

Rates of suicide attempts in Canadian youths are concerning. Adolescence is a sensitive period for the emergence of both sleep and mood problems, two major risk factors for suicidality. This naturalistic study aimed to define the sleep profile of adolescents under the combined influence of suicidality, depression and pharmacotherapy during hospitalization for a suicidal crisis.

PATIENTS/METHODS

Seventeen suicidal adolescents (15.0 + 1.2years, 82% females) with major depression were recruited from a Canadian pedopsychiatric inpatient unit. Seventeen non-depressed adolescents were retrospectively collated from another database (15.0 + 1.1years, 83% females). None of the participants had a history of sleep disorders or significant medical conditions.

RESULTS

Compared to controls, suicidal adolescents had a longer sleep onset latency (Z = -4.5, p < 0.001), longer REM latency (Z = -3.2, p = 0.001), higher percentage of NREM1 sleep t(33) = -2.6, p = 0.020), and higher REM density (Z = -2.8, p = 0.004) than controls. Higher REM density correlated with higher CDI-II scores (r = 0.55, p = 0.27) A significant interaction indicated that the two groups had similar NREM3 percentages in the first two-thirds of the night, but that the suicidal group had significantly lower NREM3 percentage than the controls in the last third of the night (F(2,66) = 3.4, p = 0.041).

CONCLUSIONS

Significant sleep abnormalities were observed during hospitalization for a suicidal crisis in a sample of depressed and mostly medicated adolescents. This included sleep initiation and REM sleep latency abnormalities, shallower sleep and high REM density. Future studies should decipher the relative effects of depression, suicidality and medication on sleep. These findings stress the need to address sleep disturbances in the management of suicidality in adolescents.

An investigation of the longitudinal relationship between sleep and depressed mood in developing teens

OBJECTIVE

The prospective, bidirectional relationship between sleep disturbance and depressed mood was assessed in a school-based sample of adolescents.

METHOD

One hundred and thirty-eight Australian adolescents (mean age time 1 =15.69, standard deviation =0.92; 64% male) completed questionnaires to assess sleep parameters and depressed mood, on two occasions over 1 year.

RESULTS

Cross-sectional associations were observed between depressed mood and sleep duration, as well as wakefulness in bed. Prospective analyses revealed depressed mood predicted less total sleep time on school nights and a longer latency to sleep onset on weekends 1 year later. There was no prospective support for sleep predicting later depressed mood.

CONCLUSION

Contrary to prediction, our results suggest in this case that depressed mood may act as a precursor to poor sleep rather than the converse.

The underlying neurobiology of key functional domains in young people with mood and anxiety disorders: a systematic review

BACKGROUND

Mood and anxiety disorders are leading causes of disability and mortality, due largely to their onset during adolescence and young adulthood and broader impact on functioning. Key factors that are associated with disability and these disorders in young people are social and economic participation (e.g. education, employment), physical health, suicide and self-harm behaviours, and alcohol and substance use. A better understanding of the objective markers (i.e. neurobiological parameters) associated with these factors is important for the development of effective early interventions that reduce the impact of disability and illness persistence.

METHODS

We systematically reviewed the literature for neurobiological parameters (i.e. neuropsychology, neuroimaging, sleep-wake and circadian biology, neurophysiology and metabolic measures) associated with functional domains in young people (12 to 30 years) with mood and/or anxiety disorders.

RESULTS

Of the one hundred and thirty-four studies selected, 7.6 % investigated social and economic participation, 2.1 % physical health, 15.3 % suicide and self-harm behaviours, 6.9 % alcohol and substance use, whereas the majority (68.1 %) focussed on clinical syndrome.

CONCLUSIONS

Despite the predominance of studies that solely examine the clinical syndrome of young people the literature also provides evidence of distinct associations among objective measures (indexing various aspects of brain circuitry) and other functional domains. We suggest that a shift in focus towards characterising the mechanisms that underlie and/or mediate multiple functional domains will optimise personalised interventions and improve illness trajectories.

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.

A meta-analysis and model of the relationship between sleep and depression in adolescents: recommendations for future research and clinical practice

The purpose of this review was to quantify the strength of evidence for a directional relationship between sleep disturbance and depression in adolescents. A literature search was conducted to identify research investigating the relationship between sleep disturbance and depression in adolescent samples (12-20 y). Twenty-three studies were identified; 13 explored associations between depression and sleep disturbance; seven examined the prospective role of sleep disturbance in the development of depression; and three investigated the role of adolescent depression in the development of subsequent sleep disturbance. Average weighted mean differences in sleep/depression-related outcome variables were calculated between adolescents with depression, and non-clinical adolescents, or those in remission. Adolescents with depression experienced significantly more wakefulness in bed (sleep onset latency, wake after sleep onset, number of awakenings and sleep efficiency), lighter sleep (more stage 1), and reported more subjective sleep disturbance. Overall effect sizes from longitudinal and treatment studies suggest sleep disturbance acts as a precursor to the development of depression. At follow-up, depressed adolescents had significantly longer sleep onset, more wake after sleep onset, and lower sleep efficiency compared to adolescents who were non-clinical, or had undergone remission. Little support was found for a predictive role of depressive symptoms in the development of sleep disturbance. Based on these findings we propose a model to understand the development of depression from initial sleep disturbance, provide recommendations for clinicians and recommendations for future research.

Polysomnographic features of early-onset depression: a meta-analysis

BACKGROUND

Undiagnosed major depressive disorder (MDD) is associated with increased morbidity in children and adolescents. This study evaluated features of sleep macro- and microarchitecture assessed by polysomnography (PSG) as diagnostic markers for MDD in children and adolescents.

METHODS

MEDLINE, PSYCINFO, EMBASE and PUBMED were searched from their availability dates to March 1st, 2013. The literature search identified 932 abstracts of which 51 studies were retrieved and 28 were included in the analysis. Study design, features of sleep macro- and microarchitecture, demographic and clinical characteristics of study groups were extracted for each study.

RESULTS

There were modest differences on sleep macroarchitecture between children and adolescents with MDD and healthy controls. The most robust difference was found in sleep latency, 31% of adolescents with MDD had increased sleep latency. Age, suicidal ideation, suicidal behavior, and psychiatric comorbidities were significant predictors of sleep macroarchitecture. Modest differences were found for sleep microarchitecture, intrahemispheric and interhemispheric temporal coherence was decreased in a third of patients with MDD. Age was a significant predictor of sleep microarchitecture.

LIMITATIONS

This meta-analysis is limited by the small number of studies on sleep macroarchitecture in children with MDD and studies on sleep microarchitecture overall and by the heterogeneity in methodology between studies.

CONCLUSIONS

This synthetic review of the existing literature is among the largest to quantitatively assess impaired sleep as a diagnostic marker for MDD in children and adolescents. Knowledge of sleep macro- and microarchitecture in early-onset MDD may aid the clinician in developing a treatment strategy for MDD-related sleep symptoms in a subset of patients.

Randomised, double-blind study of the effects of oxybutynin, tolterodine, trospium chloride and placebo on sleep in healthy young volunteers

OBJECTIVE

Central nervous effects of oral anticholinergics may limit the success of incontinence therapy and patient compliance. Only a few studies investigating this topic are available. This study was conducted to determine whether oral anticholinergics alter sleep and psychometric test parameters.

DESIGN

Randomised, double-blind, crossover, placebo-controlled study.

STUDY PARTICIPANTS

24 healthy volunteers (age 22-36 years) without sleeprelated problems.

INTERVENTIONS

Polysomnographic recordings, sleep questionnaires and psychometric tests (the number combination test [Zahlen-Verbindungs Test; ZVT] and the d2 attention test) were performed following single doses of oxybutynin 15mg, tolterodine 4mg, trospium chloride 45mg or placebo, each separated by an 8-day washout period.

RESULTS

Rapid eye movement (REM) sleep (relative to total sleep time) was the primary parameter of polysomnography. The REM sleep for oxybutynin was significantly lower than that for trospium chloride (18.4% vs 20.2%; p < 0.05) and lower than that for placebo (20.1%; ns). The number combination test (ZVT), the primary parameter of cognitive function, and the d2 test did not reveal any differences in reaction time. With regard to the other sleep parameters, the REM latency for oxybutynin was clearly higher than that for placebo, trospium chloride and tolterodine. Effects on non-REM sleep were observed only after administration of oxybutynin compared with placebo.

CONCLUSIONS

Oxybutynin influenced sleep structure, as was reflected by REM suppression and mild sedation, while subjective parameters and psychometric tests remained unaffected. The sleep and psychometric test values for tolterodine and trospium chloride were comparable to those of placebo. The clinical relevance of these effects is small in healthy young volunteers, but these results cannot be extended to the elderly.

Sleep Disturbances in Pediatric Depression

Depressive illness beginning early in life can have serious developmental and functional consequences. Therefore, understanding its etiology and pathophysiology during this developmental stage is critical for developing effective prevention and intervention strategies. There is considerable evidence of sleep alterations in adult major depressive disorder. However, studies in children and adolescents have not found consistent changes in sleep architecture paralleling adult depression. This review article summarizes sleep polysomnography research in early-onset depression, highlighting the factors associated with variable findings across studies. In addition, potential avenues for future research will be suggested in order to develop more comprehensive theoretical models and interventions for pediatric depression.

Mood-related sleep problems in children and adolescents

Sleep problems are an essential part of the current diagnostic criteria for depressive and bipolar disorders in children and adolescents. Whereas many studies have reported subjective sleep problems in youth with depression or bipolar disorder, except for reduced rapid eye movement latency associated with depression, few objective mood-related sleep abnormalities have been consistently identified. Recent technologic advances, such as spectral EEG and actigraphy, hold promise for revealing additional objective disturbances. There are presently few evidence-based published practice recommendations for mood-related sleep problems in youth. In this article, the authors chronologically review research on the phenomenology and treatment of sleep difficulties in youth with depressive and bipolar disorders and present research-based and clinically guided recommendations for the assessment and treatment of these problems.

Electroencephalographic sleep and hypothalamic-pituitary-adrenal changes from episode to recovery in depressed adolescents

OBJECTIVE

The study examined electroencephalographic (EEG) sleep and hypothalamic-pituitary-adrenal (HPA) changes associated with depressive episode and during recovery in adolescent depression.

METHODS

Sixteen adolescents with major depressive disorder and 16 volunteers with no personal or family history of psychiatric disorder participated in a three-night EEG sleep protocol along with nocturnal urinary free cortisol (NUFC). Depressed subjects also were restudied during stable remission from the depressive episode.

RESULTS

Compared with controls, depressed adolescents had significantly reduced sleep efficiency, shorter latency to rapid eye movement (REM) sleep, increased phasic REM sleep, and elevated NUFC excretion. Among depressed subjects, EEG sleep values did not change significantly from episode to remission. NUFC excretion reduced significantly during remission from the depressive episode.

CONCLUSIONS

The findings that EEG sleep measures are independent of clinical state, whereas HPA variables are state dependent, suggest that sleep and HPA measures make a differential contribution to our understanding of the pathophysiology and prognosis of mood disorders in adolescent patients.

Sleep and youth suicidal behavior: a neglected field

PURPOSE OF REVIEW

Sleep undergoes substantial changes during adolescence and suicide risk begins to increase during this period as well. This review focuses on recent literature on the relationship between sleep and suicidal behavior and proposes directions for future research.

RECENT FINDINGS

Adolescent sleep is characterized by widespread sleep restriction, irregular sleep schedules, daytime sleepiness, and elevated risk for sleep disturbances. More research on adolescent sleep and psychosocial impairment, psychiatric disorders, and suicidal behavior has been conducted. Suicidal psychiatric patients had more sleep disturbances including insomnia, hypersomnia, or nightmares than nonsuicidal patients. Shorter rapid eye movement latency and increased rapid eye movement activity have been noted to be a marker of suicidality in psychiatric patients. Epidemiological studies have demonstrated that insomnia, nightmares, and sleep insufficiency are associated with elevated risk for suicide. Although the link between insomnia and suicidal behavior appears to be mediated by depression, existing data suggest an independent predictive role of nightmares in future suicidal behavior.

SUMMARY

Sleep loss or disturbances are likely to signal an increased risk of future suicidal action in adolescents. Large-scale prospective studies and neurobiological studies are needed for a better understanding of the complex relationship between sleep, psychopathology, and youth suicidal behavior.

Sleep microarchitecture in childhood and adolescent depression: temporal coherence

Previous work has indicated that low temporal coherence of ultradian sleep EEG rhythms is characteristic of depressed patients and women in particular. It may also be evident in depressed children and adolescents, although most published studies are limited in sample size. The present study evaluated temporal coherence of sleep EEG rhythms in 173 children and adolescents 8-17 years of age, including 97 who met criteria for major depressive disorder (MDD) and were symptomatic but unmedicated at the time of study and 76 healthy controls. Temporal coherence of all-night sleep EEG rhythms was evaluated on the second of two nights in the laboratory. Data were coded for diagnostic group, gender and age and subjected to MANOVAs. Temporal coherence was significantly lower in adolescents with MDD, compared to healthy controls. Findings were most robust for coherence between left and right beta and between delta and beta in both hemispheres. Both gender and age strongly influenced between-group differences, with the lowest temporal coherence among MDD girls, even in those under 13 years of age. In conclusion, early onset depression is associated with a reduction in synchronization of sleep EEG rhythms that shows a differential maturational course in boys and girls.

Sleep and depression in children and adolescents

There is considerable research evidence suggesting that sleep is biologically linked to mood disorders in adults. However, polysomographic and neuroendocrine studies in children and adolescents have not found consistent changes in sleep architecture paralleling adult major depression. This review provides a detailed description of sleep research that has been conducted in early-onset affective disorders, uncovers the potential limitations of the available data, and formulates future research directions in this important subject.

Sleep disturbances and childhood sexual abuse

OBJECTIVE

This longitudinal, prospective study examined the relationship between childhood sexual abuse and later sleep problems in adolescence while taking into account cooccurring psychopathology that is closely related to sleep disruption [e.g., depression and posttraumatic stress disorder (PTSD)].

METHOD

Sleep disturbances in 147 females (78 sexually abused; 69 comparison) were assessed 10 years after disclosure of substantiated abuse. The follow-up protocol included self-report questions regarding typical sleeping patterns and sleep disturbances as well as measures of depression, PTSD, and lifetime victimization histories.

RESULTS

Sleep disturbances correlated significantly with both depression and PTSD. Hierarchical regression analysis showed that sexually abused participants reported significantly greater rates of sleep disturbances than comparison participants above and beyond depression and PTSD. Sleep disturbances were related to revictimization rates independent of sexual abuse, depression, and PTSD.

CONCLUSIONS

Assessments of sleep disturbances should be integrated into standard of care for adolescents who have experienced sexual abuse.

Effects on sleep of anticholinergics used for overactive bladder treatment in healthy volunteers aged > or = 50 years

OBJECTIVE

To study the influence of oxybutynin, tolterodine or trospium chloride, anticholinergics used to treat bladder overactivity, on sleep and the cognitive skills of healthy volunteers aged > or = 50 years.

SUBJECTS AND METHODS

In a randomized, double-blind, placebo-controlled study with a crossover design, 24 healthy sleepers (12 men and 12 women) aged 51-65 years underwent polysomnographic recordings and cognitive tests in a sleep laboratory. Study medications were given as a single dose containing the total recommended daily dose.

RESULTS

There was a significant reduction in rapid-eye movement (REM) sleep of approximately 15% and a slightly (but not significantly) greater REM latency after oxybutynin and tolterodine than with placebo. After trospium chloride, REM duration and latency were comparable with placebo. There was no effect of the tested anticholinergics on cognitive and subjective sleep variables.

CONCLUSION

Individuals aged > or = 50 years had a more distinct impairment of REM sleep after oxybutynin and tolterodine than had young people, but the reduction in REM sleep did not reach a pathological degree in this single-dose study. There was no apparent impairment of concentration or cognitive function, but impairment of cognitive function and neuropsychological side-effects cannot be excluded, especially when elderly patients with impaired REM sleep from various psychiatric diseases (e.g. depression) and/or sleep disturbances are given oxybutynin or tolterodine in long-term treatment.

Sleep-wake effects of meta-chlorophenyl piperazine and mianserin in the behaviorally depressed rat

The present study examined the effects of meta-chlorophenyl piperazine (mCPP) and mianserin on the sleep-wake cycle of the clomipramine-induced behaviorally screened depressed rats. Six-hour polygraphic recordings were made between 06:00 and 12:00 h, after a single injection of either saline or mianserin or mCPP into the lateral cerebral ventricle (i.c.v.) of both the depressed (n=12) and control rats (n=12). The injection of mCPP in the depressed rats caused a significant reduction in the total duration and number of rapid eye movement (REM) sleep episodes while it increased the REM sleep onset latency compared to the control saline injections. The injection of mianserin in the depressed rats also caused a significant reduction in the total duration and number of REM sleep episodes without changing the REM sleep latency. These results demonstrate for the first time that the central administration of mCPP and mianserin could act as an antidepressant in the clomipramine-induced rat model of depression.

Temporal coherence in ultradian sleep EEG rhythms in a never-depressed, high-risk cohort of female adolescents

BACKGROUND

Previous work has indicated that low temporal coherence of ultradian sleep electroencephalographic rhythms is characteristic of depressed patients and of depressed women, in particular. It may also be evident in one quarter of those at high risk, based on a family history of depression.

METHODS

The present study evaluated temporal coherence of sleep electroencephalographic rhythms in 41 adolescent girls with a maternal history of depression (high risk) and 40 healthy controls (low risk). The entire sample was followed clinically every 6 months for 2 years.

RESULTS

Temporal coherence was significantly lower among the high-risk girls than in controls. Regression analyses predicted group from coherence values and correctly classified 70% of the high-risk group with a false-positive rate of 5% among controls. Moreover, 54% of the high-risk girls were identified with extreme low coherence. On clinical follow up, 14 girls showed depressive symptoms, 9 in the high-risk group (22.5%) and 5 controls (12.2%). Six met DSM-IV criteria for first-episode major depressive disorder, five high-risk and one control. Most importantly, 41% of those identified as having the most abnormal coherence values either showed symptoms of depression or met diagnostic criteria upon follow up.

CONCLUSIONS

Low temporal coherence is evident in adolescent girls at high risk for depression. The more abnormal the coherence, the greater the risk of a first episode of major depressive disorder within 2 years of sleep study, approximately 10 times greater than in controls.

Sleep and depression--results from psychobiological studies: an overview

Disturbances of sleep are typical for most depressed patients and belong to the core symptoms of the disorder. Polysomnographic sleep research has demonstrated that besides disturbances of sleep continuity, in depression sleep is characterized by a reduction of slow wave sleep and a disinhibition of REM sleep, with a shortening of REM latency, a prolongation of the first REM period and increased REM density. These findings have stimulated many sleep studies in depressive patients and patients with other psychiatric disorders. In the meantime, several theoretical models, originating from basic research, have been developed to explain sleep abnormalities of depression, like the two-process-model of sleep and sleep regulation, the GRF/CRF imbalance model and the reciprocal interaction model of non-REM and REM sleep regulation. Interestingly, most of the effective antidepressant agents suppress REM sleep. Furthermore, manipulations of the sleep-wake cycle, like sleep deprivation or a phase advance of the sleep period, alleviate depressive symptoms. These data indicate a strong bi-directional relationship between sleep, sleep alterations and depression.

Premorbid polysomnographic signs in depressed adolescents: a reanalysis of EEG sleep after longitudinal follow-up in adulthood

BACKGROUND

This is a report of a clinical follow-up study (10-15 years later as young adults) of adolescent major depressives and normal control subjects. Polysomnographic data were obtained during the original study period when the subjects were adolescent (time 1). With clinical follow-up (time 2) assessments in hand, our objective was to ascertain whether there were any premorbid polysomnographic signs associated with depression during adolescence.

METHODS

Based upon initial (during adolescence) and follow-up clinical assessments (as adults), new subject groupings were generated: depression-free normal subjects and original normal subjects who experienced a depressive episode during the follow-up period (latent depressives). Suicidality and recurrence of depression were also examined. Multivariate analysis of covariance was used to analyze group differences in sleep measures and logistic regression for predicting three outcomes: lifetime depression, lifetime suicidality, and recurrence.

RESULTS

Comparison of the depression-free normal subjects, the latent depressives, and the original major depressives revealed significant differences for sleep latency and sleep period time. Comparing all lifetime depressives (original major depressives and the latent depressives) to depression-free normal subjects revealed significantly more stages 3 and 4 combined (ST34) sleep and greater sleep period times among the depressives. An analysis involving the presence or absence of suicidality revealed no overall significant differences between the groups. Comparison of the lifetime depressives grouped by nonrecurrent and recurrent depressive course to the depression-free normal subjects revealed significant difference for sleep period time. Using logistic regression, we found that a longer sleep latency and sleep period time significantly predicted lifetime depression. Gender, ST34 sleep, and an interaction term for ST34 sleep and REM latency significantly predicted lifetime suicidality.

CONCLUSIONS

There was evidence of premorbid sleep abnormalities during adolescence. A general pattern of sleep disruption around sleep onset and during the first 100 min of the sleep period and overall sleep was evident among the major and lifetime depressives, involving sleep latency (initial insomnia), sleep period time (hypersomnia), REM latency, and slow-wave sleep. This adds to the body of literature that highlights the importance of the first 100 min of the sleep period in depression.

Delta sleep EEG in depressed adolescent females and healthy controls

BACKGROUND

Quantitative EEG studies have identified a number of sleep abnormalities in adults with major depressive disorders (MDD), including a reduction in the amplitude of delta activity during NREM sleep. To date, these methodologies have not been used in early onset MDD.

METHODS

Delta activity during NREM sleep was compared in eight symptomatic but unmedicated adolescent females with MDD and eight age- and gender-matched healthy controls.

RESULTS

The depressed group showed significantly lower delta amplitude and power in the first NREM sleep period. By contrast, standard sleep architecture did not differentiate between groups.

LIMITATIONS

Given the sample size, this study is best viewed as tentative. In addition, it has yet to be determined whether adolescent males with MDD also show delta sleep abnormalities. Further, failure to find between-group differences in REM latency or other macroarchitectural measures may be due to the small sample size.

CONCLUSIONS

The findings of this study underscore the utility of quantitative sleep EEG techniques in early onset MDD. The results of the present study do, however, diverge from reports in adults with MDD, where delta abnormalities are more prevalent in men. Such findings suggest that the maturational time course of sleep EEG disturbances may differ for males and females with depression. Early emergence of delta abnormalities in depression may be of relevance to clinical course of illness.

Ultradian rhythms and temporal coherence in sleep EEG in depressed children and adolescents

BACKGROUND

It has been suggested that a primary ultradian (80-120 minute) rhythm disturbance in EEG underlies sleep abnormalities in adults with depression. The present study evaluated ultradian rhythm disturbances in childhood and adolescent depression.

METHODS

Sleep macroarchitecture and temporal coherence in quantitative EEG rhythms were investigated in 50 medication-free outpatients with major depression (25 children and 25 adolescents) and 15 healthy normal controls (5 children and 10 adolescents).

RESULTS

Few of the macroarchitectural measures showed significant group effects. In fact, age and sex effects were stronger than disease-dependent components. Temporal coherence of EEG rhythms during sleep did differentiate those with MDD from controls. Both depressed children and adolescents had lower intrahemispheric coherence, whereas interhemispheric was only lower in depressed adolescents in comparison with controls. Gender differences were evident in adolescents, but not children, with MDD with lowest interhemispheric coherence in adolescent girls.

CONCLUSIONS

These findings are in keeping with increased risk for depression in females beginning at adolescence and extending throughout adulthood. It was suggested that low temporal coherence in depression reflects a disruption in the fundamental basic rest-activity cycle of arousal and organization in the brain that is strongly influenced by gender.