Sleep onset abnormalities in depressed adolescents

Sleep duration and depression among adolescents: Mediation effect of collective integration

Adolescence is a time of dramatic physical and mental change when adolescents are extremely vulnerable to various mental health problems. Depression and poor sleep duration are increasingly common among adolescents. This study is mainly aimed to verify the important mediating role of collective integration on sleep duration and depression and examine the interrelationship between sleep duration and depression in adolescents longitudinally. The data were obtained from the Wave 1 (in 2013-2014) and Wave 2 (in 2014-2015) longitudinal surveys of China Education Panel Survey (CEPS). The analytic sample in the present study included 8,829 seventh-grade students aged about 14 years (51.50% boys and 48.50% girls). A structural equation modeling (SEM) was used to investigate parent-child/teacher factors affecting adolescent sleep duration and depression, and Monte Carlo resampling with R was employed to confirm the significance of the mediation effects of collective integration. An autoregressive cross-lagged model was employed to analyze the interrelationship between adolescent sleep duration and depression. The findings were as follows. Firstly, collective integration strongly mediated the relationships among academic self-efficacy, parental involvement, teacher praise/criticism, sleep duration, and depression. Secondly, sleep duration and depression were found to have enduring effects and have effects on each other. Thirdly, parental involvement and teacher praise were positively associated with sleep quality and negatively associated with depression. Teacher criticism was negatively associated with sleep quality and positively associated with depression. Compared with teacher praise, teacher criticism has stronger effects on youth sleep duration and depression. In conclusion, improving sleep problems and depression in adolescents as early as possible can stop the persistent and long-term consequences of these problems. Increasing teacher praise, decreasing teacher criticism, and increasing adolescents' collective integration were effective ways to improve adolescents' sleep duration and mediate depression.

[Sleep disturbances and their associations with disorders in emotional sphere and behavior in children]

The paper addresses associations between sleep disorders and emotional and behavioral disturbances in children. These associations are considered in a view of commonly found co-occurrences of sleep problems, signs of anxiety and depression, oppositional-defiant behavior, and increased aggressiveness. The authors put forward a conception of reciprocal influences of these disturbances and provide information on potential physiological mechanisms responsible for associations between sleep problems and emotional and behavioral disturbances in children. Attention is drawn to hypothalamus-hypophysis-adrenal axis activation, serotonergic and aminergic systems imbalance, impaired melatonin and orexins production. Possibility of an existing pattern encompassing sleep problems, emotional and behavioral disturbances is discussed. Practical recommendations aimed at timely identification and treatment of the mentioned disorders are suggested.

The falling asleep process in adolescents

STUDY OBJECTIVES

To investigate the pre-sleep psychophysiological state and the arousal deactivation process across the sleep onset (SO) transition in adolescents.

METHODS

Data were collected from a laboratory overnight recording in 102 healthy adolescents (48 girls, 12-20 years old). Measures included pre-sleep self-reported cognitive/somatic arousal, and cortical electroencephalographic (EEG) and electrocardiographic activity across the SO transition.

RESULTS

Adolescent girls, compared with boys, reported higher pre-sleep cognitive activation (p = 0.025) and took longer to fall asleep (p < 0.05), as defined with polysomnography. Girls also showed a less smooth progression from wake-to-sleep compared with boys (p = 0.022). In both sexes, heart rate (HR) dropped at a rate of ~0.52 beats per minute in the 5 minutes preceding SO, and continued to drop, at a slower rate, during the 5 minutes following SO (p < 0.05). Older girls had a higher HR overall in the pre-sleep period and across SO, compared to younger girls and boys (p < 0.05). The EEG showed a progressive cortical synchronization, with increases in Delta relative power and reductions in Alpha, Sigma, Beta1, and Beta2 relative powers (p < 0.05) in the approach to sleep, in both sexes. Delta relative power was lower and Theta, Alpha, and Sigma relative powers were higher in older compared to younger adolescents at bedtime and across SO (p < 0.05).

CONCLUSIONS

Our findings show the dynamics of the cortical-cardiac de-arousing process across the SO transition in a non-clinical sample of healthy adolescents. Findings suggest a female-specific vulnerability to inefficient sleep initiation, which may contribute to their greater risk for developing insomnia.

Association between depressive symptoms and sleep neurophysiology in early adolescence

BACKGROUND

Depression is highly prevalent among adolescents, and depressive symptoms rise rapidly during early adolescence. Depression is often accompanied by subjective sleep complaints and alterations in sleep neurophysiology. In this study, we examine whether depressive symptoms, measured on a continuum, are associated with subjective and objective (sleep architecture and neurophysiology) measures of sleep in early adolescence.

METHODS

High-density sleep EEG, actigraphy, and self-reported sleep were measured in 52 early adolescents (12.31 years; SD: 1.121; 25 female). Depressive symptoms were measured on a continuum using the Center for Epidemiological Studies Depression Scale (CES-D). The association between depressive symptoms and 2 weeks of actigraphy, self-reported sleep, sleep architecture, and sleep neurophysiology (slow wave activity and sigma power) was determined via multiple linear regression with factors age, sex, and pubertal status.

RESULTS

Despite no association between polysomnography measures of sleep quality and depressive symptoms, individuals with more depressive symptoms manifested worse actigraphically measured sleep. Less sleep spindle activity, as reflected in nonrapid eye movement sleep sigma power, was associated with more depressive symptoms over a large cluster encompassing temporal, parietal, and occipital regions. Furthermore, worse subjectively reported sleep quality was also associated with less sigma power over these same areas. Puberty, age, and sex did not impact this association.

CONCLUSIONS

Sleep spindles have been hypothesized to protect sleep against environmental disturbances. Thus, diminished spindle power may be a subtle sign of disrupted sleep and its association with depressive symptoms in early adolescence may signal vulnerability for depression.

Association Between Sleep Problems and Symptoms of Attention Deficit Hyperactivity Disorder in Adolescence: Results From a Large Population-Based Study

Sleep problems and symptoms of ADHD are common in adolescence, but detailed epidemiological assessment of their association is lacking. Using data from a recent population-based study, 9,846 adolescents aged 16 to 19 provided detailed information on sleep and symptoms of ADHD. Results confirmed a large overlap between self-reported symptoms of ADHD and all sleep variables studied. Symptoms of ADHD were linked to shorter sleep duration, longer sleep latency, and nocturnal wake time, as well as larger sleep deficiency. ADHD symptoms also increased the odds of insomnia and delayed sleep phase syndrome. The associations were only partially explained by confounders (mainly depression). The findings suggest that sleep problems should be included as a treatment target in efforts to reduce symptoms of ADHD in adolescence.

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

Increased frontal sleep slow wave activity in adolescents with major depression

Sleep slow wave activity (SWA), the major electrophysiological characteristic of deep sleep, mirrors both cortical restructuring and functioning. The incidence of Major Depressive Disorder (MDD) substantially rises during the vulnerable developmental phase of adolescence, where essential cortical restructuring is taking place. The goal of this study was to assess characteristics of SWA topography in adolescents with MDD, in order to assess abnormalities in both cortical restructuring and functioning on a local level. All night high-density EEG was recorded in 15 patients meeting DSM-5 criteria for MDD and 15 sex- and age-matched healthy controls. The actual symptom severity was assessed using the Children's Depression Rating Scale-Revised (CDRS-R). Topographical power maps were calculated based on the average SWA of the first non-rapid eye movement (NREM) sleep episode. Depressed adolescents exhibited significantly more SWA in a cluster of frontal electrodes compared to controls. SWA over frontal brain regions correlated positively with the CDRS-R subscore "morbid thoughts". Self-reported sleep latency was significantly higher in depressed adolescents compared to controls whereas sleep architecture did not differ between the groups. Higher frontal SWA in depressed adolescents may represent a promising biomarker tracing cortical regions of intense use and/or restructuring.

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.

Insufficient sleep in adolescents and young adults: an update on causes and consequences

Chronic sleep loss and associated sleepiness and daytime impairments in adolescence are a serious threat to the academic success, health, and safety of our nation's youth and an important public health issue. Understanding the extent and potential short- and long-term repercussions of sleep restriction, as well as the unhealthy sleep practices and environmental factors that contribute to sleep loss in adolescents, is key in setting public policies to mitigate these effects and in counseling patients and families in the clinical setting. This report reviews the current literature on sleep patterns in adolescents, factors contributing to chronic sleep loss (ie, electronic media use, caffeine consumption), and health-related consequences, such as depression, increased obesity risk, and higher rates of drowsy driving accidents. The report also discusses the potential role of later school start times as a means of reducing adolescent sleepiness.

Sleep problems and depression in adolescence: results from a large population-based study of Norwegian adolescents aged 16-18 years

Both sleep problems and depression are common problems in adolescence, but well-defined large epidemiological studies on the relationship are missing in this age group. The aim of this study was to examine the association between depression and several sleep parameters, including insomnia, in a population-based study of adolescents aged 16-18 years, and to explore potential gender differences. A large population-based study in Hordaland County in Norway conducted in 2012, the ung@hordaland study, surveyed 10,220 adolescents aged 16-18 years (54% girls) about sleep and depression. The sleep assessment included measures of the basic sleep parameters for weekdays and weekends. Depression was defined as scoring above the 90th percentile on the total score of Short Moods and Feelings Questionnaire (SMFQ). There was a large overlap between insomnia and depression in both genders and across depressive symptoms. Depressed adolescents exhibited significantly shorter sleep duration and time in bed as well as significantly longer sleep onset latency (SOL) and wake after sleep onset (WASO). Adolescents with insomnia had a 4- to 5-fold increased odds of depression compared to good sleepers. There was also a significant interaction between insomnia, sleep duration and depression, with a more than eightfold increase in odds of depression for those who met criteria for insomnia and who slept <6 h. These associations held for both genders, but were stronger in boys. To the best of our knowledge, this is the first population-based study to investigate sleep and insomnia in relation to depression among adolescents. The findings call for increased awareness of sleep problems and depression as a major public health issue.

Suicidal ideations and sleep-related problems in early adolescence

AIMS

Suicidal ideation and sleep-related problems are associated with many common psychopathological entities in early adolescence. This study examined possible association between suicidal ideation and sleep-related problems.

METHODS

A cross-sectional study was performed in classroom settings at 840 early adolescents 11-13 years of age. Of those, 791 adolescents fully completed the data and thus represent an actual sample. Suicidal ideations were assessed with three dichotomous (yes/no) items: 'I often think about death'; 'I wish I was dead'; 'I often think about suicide.' A composite measure of perceived sleep-related problems was formed by combining items from the Junior Eysenck Personality Questionnaire (Do you find it hard to sleep at night because you are worrying about things?), Children Depression Inventory (It is hard for me to fall asleep at night), and two additional dichotomous questions (I often was not able to fall asleep because of worrying; At times I was not able to stay asleep because of worrying). This score mainly assessed difficulties in initiating or maintaining sleep.

RESULTS

A total of 7.1% adolescents reported suicidal ideation and 86.7% of them had sleep problems. Sleep-related problems were associated with any suicidal ideation and each type of ideation separately.

CONCLUSION

This study suggests association of sleep problems and suicidal ideations in early adolescence. Therefore, clinicians should evaluate this population for sleep disturbances, as they might be a marker of increased risk for suicidality.

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.

Developmental changes in sleep and their relationships to psychiatric illnesses

PURPOSE OF REVIEW

Sleep undergoes major changes during development. Its relationship to the complex process of maturation in health and disease has recently received increased attention. This review aims to highlight the recent literature examining the interplay of altered sleep, brain development and emerging psychiatric illnesses in children and adolescents.

RECENT FINDINGS

In addition to a temporal relationship of sleep disturbances preceding the onset of psychiatric illnesses, a bi-directional interaction of altered sleep and symptom severity has increasingly been shown. Sleep architecture shows drastic age-dependent alterations on a structural level during the first 2 decades of life. However, findings regarding disease-specific patterns have remained inconsistent. On a functional level, recent evidence about sleep electroencephalographic characteristics points to a close relationship between slow waves, reflecting the depth of sleep, and cortical plasticity.

SUMMARY

Sleep provides a rich source of information to gain insight into both the healthy and disturbed processes of brain function and maturation. Emerging data suggest that the investigation of slow wave activity is a novel and promising tool for monitoring both of these processes. It is important to understand when and how deviations from typical developmental sleep alterations occur in order to improve prevention and early treatment of disorders affecting a substantial number of children and adolescents.

Sleep disturbance in euthymic bipolar patients

Sleep disturbance is a common feature during mood episodes in bipolar disorder. The aim of this study was to investigate the prevalence of such symptoms among euthymic bipolar patients, and their association with risk for mood episode recurrence. A cohort of bipolar I and II subjects participating in the Systematic Treatment Enhancement Program for Bipolar Disorder who were euthymic for at least 8 weeks were included in this analysis. Survival analysis was used to examine the association between sleep disturbance on the Montgomery-Asberg Depression Rating Scale (MADRS) and recurrence risk. A total of 73/483 bipolar I and II subjects reported at least mild sleep disturbance (MADRS sleep item ≥2) for the week prior to study entry. The presence of sleep problems was associated with a history of psychosis, number of previous suicide attempts, and anticonvulsant use. Sleep disturbance at study entry was significantly associated with risk for mood episode recurrence. Sleep disturbance is not uncommon between episodes for individuals with bipolar disorder and may be associated with a more severe course of illness. This suggests that sleep disturbance is an important prodromal symptom of bipolar disorder and should be considered a target for pharmacologic or psychosocial maintenance treatment.

Double trouble? The effects of sleep deprivation and chronotype on adolescent affect

BACKGROUND

  Two understudied risk factors that have been linked to emotional difficulties in adolescence are chronotype and sleep deprivation. This study extended past research by using an experimental design to investigate the role of sleep deprivation and chronotype on emotion in adolescents. It was hypothesized that sleep deprivation and an evening chronotype would be associated with decreased positive affect (PA), increased negative affect (NA), and lower positivity ratios.

METHODS

  Forty-seven healthy adolescents (aged 10-15 for girls, 11-16 for boys) participated in a sleep deprivation and a rested condition. A subsample of 24 adolescents was selected on the basis of extreme morningness or eveningness scores (based on outer quartiles of scores on the Children's Morningness-Eveningness Preferences Scale). PA and NA were measured using the Positive and Negative Affect Schedule for Children, and positivity ratios were calculated by dividing PA by NA.

RESULTS

  Participants reported less positive affect and lower positivity ratios when sleep deprived, relative to when rested. Evening chronotypes reported less positive affect and lower positivity ratios than morning chronotypes in both rested and sleep deprivation conditions.

CONCLUSIONS

  These findings extend previous research by suggesting that adolescents are adversely impacted by sleep deprivation, and that an evening chronotype might serve as a useful marker of emotional vulnerability. Early intervention and prevention strategies can focus on improving sleep and on using chronotherapy principles to reduce eveningness.

Pain and sleep-wake disturbances in adolescents with depressive disorders

The aims of this study were to (a) assess and compare sleep disturbances (including daytime and nighttime sleep patterns) in adolescents with depressive disorders and healthy peers, (b) examine the prevalence of pain in adolescents with depressive disorders and healthy peers, and (c) examine pubertal development, pain intensity, and depressive symptom severity as predictors of sleep disturbance. One hundred six adolescents (46 depressed, 60 healthy), 12 to 18 years (M = 15.10 years; 67% female; 77% Caucasian) completed subjective measures of sleep, presleep arousal, fatigue, and pain. Participants also underwent 10 days of actigraphic monitoring to assess nighttime and daytime sleep duration, sleep efficiency, and wake after sleep onset. Results indicated that youth with depression exhibited greater sleep disturbances on subjective and actigraphic sleep variables than healthy controls. Depressed youth also reported more frequent and severe pain than healthy youth. Linear regression analysis indicated that pain intensity and depressive symptoms predicted worse sleep quality across groups. The interaction term was also significant, such that adolescents with high levels of depressive symptoms had poor sleep quality when pain intensity levels were high. These results indicate that sleep is important to assess in youth with depression, and that pain may be an important target for sleep intervention in this population.

Associations between psychiatric comorbidities and sleep disturbances in children with attention-deficit/hyperactivity disorder

OBJECTIVE

Children with attention-deficit/hyperactivity disorder (ADHD) often have sleep complaints and also higher rates of psychiatric comorbidities such as mood and anxiety disorders that may affect sleep. The authors hypothesized that children with ADHD and psychiatric comorbidities would have higher overall sleep disturbance scores as measured by a sleep questionnaire than children with ADHD without comorbidities.

METHODS

This cross-sectional analysis in an academic center studied 317 children with ADHD; 195 subjects had no comorbid conditions, 60 were anxious and 62 were depressed. Participants completed the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present State, 4th Revised Edition and the Children's Sleep Habits Questionnaire.

RESULTS

Median age (range) was 8.9 (6-18.7) years; 78% were male. Median (interquartile range) Total Sleep Disturbance Score (TSDS) on Children's Sleep Habits Questionnaire for subjects with no comorbidities was 44 (40-49); anxiety, 48 (43-54); and depression, 46 (41-52). Compared with subjects without comorbidities, TSDS in anxious subjects was greater (p = .008). TSDS in depressed subjects was not significantly different. Compared with subjects without comorbidities, anxious subjects had higher Bedtime Resistance, Sleep Onset Delay, and Night Wakings subscales (p = .03, .007, and .007, respectively); depressed subjects had higher Sleep Onset Delay and Sleep Duration subscales (p = .003 and .01, respectively).

CONCLUSIONS

Anxiety in children with ADHD contributed to higher overall sleep disturbance scores, compared with children with ADHD alone. Both comorbidities were associated with higher Sleep Onset Latency subscale scores. Further study of the impact of psychiatric comorbidities on sleep in children with ADHD is warranted.

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.

Complaints of difficulty to fall asleep increase the risk of depression in later life: the health in men study

OBJECTIVES

To determine if complaints of poor sleep are associated with incident depression in older men.

METHODS

Cohort study with an average follow up period of 6 years (range 3 months to 8.5 years). Participants were 5127 community-dwelling Western Australian older men aged 70-90 years who provided information about sleep problems. The primary outcome of interest of the study was a recorded diagnosis of depressive episode, recurrent depressive disorder or dysthymia in the Western Australian Data Linkage System. Participants completed a health questionnaire that included questions assessing difficulty falling asleep, remaining awake, as well as early morning awakening. Other measured factors included age, education, country of birth, living arrangements, social support, smoking, body mass index, and prevalent diabetes, hypertension, arthritis, chronic respiratory diseases, coronary artery disease, stroke, and cancer. Biochemical measurement of C-reactive protein, testosterone and plasma homocysteine were available for 3800 men.

RESULTS

We found that 60% of men reported at least one sleep problem and that the unadjusted hazard ratio (HR) of depression was higher in men who complained of difficulties to initiate sleep (HR = 2.19, 95% confidence interval--95% CI = 1.47-3.27) or who remained awake most of the night (HR = 1.94, 95% CI = 1.15-3.27). There was no association between early morning awakening and incident depression. The association between incident depression and subjective difficulty falling asleep remained after the analyses were adjusted for other measured factors (HR = 1.83, 95% CI = 1.20-2.79). The association between depression and remaining awake was no longer significant once the analyses were adjusted for confounding (HR = 1.43, 95% CI = 0.81-2.53). A sensitivity analysis confirmed these results.

LIMITATIONS

The evaluation of the exposure (sleep disturbance) was limited to self-rating questions that were not externally validated. The diagnosis of depression was based on administrative record linkage rather than structure clinical interviews. The observational nature of the study limits our ability to ascribe a causal relationship between complaints of poor sleep and incident depression.

CONCLUSIONS

Complaints of difficulty falling asleep increase the risk of incident depression in older men. Clarifying the mechanisms that underlie this association should become an international research priority, as they may contribute to guide interventions designed to decrease the burden of depression in later life.

Severe mood dysregulation: in the "light" of circadian functioning

Severe affective and behavioral dysregulation, labeled as severe mood dysregulation (SMD), is a widely spread phenomenon among adolescent psychiatric patients. This phenotype constitutes severe impairment across multiple settings, including various symptoms, such as non-episodic anger, mood instability, and hyperarousal. Moreover, SMD patients often show depression and reduced need for sleep. Despite a lifetime prevalence of 3.3%, systematic research is still scarce, and treatments that have been established do not account for the range of symptoms present in SMD. Considering the circadian dysfunctions, two hormones, melatonin and cortisol, are essential. When these hormones are dysregulated, the circadian rhythm gets out of synchrony. Since evidence is emerging showing that the worse the sleep-wake cycle is entrained, the worse the psychiatric symptoms are depicted, the importance of proper circadian functioning becomes clear. Chronotherapy as the controlled exposure to environmental stimuli (e.g. light) acting on biological rhythms has shown therapeutic effects. In both seasonal and major depression chronotherapy has been implemented, decreasing depressive symptoms and stabilizing circadian rhythms. Preliminary evidence from SMD related disorders, namely attention-deficit/hyperactivity disorder and pediatric bipolar depression, indicates that morning light therapy elicits positive influences on other symptoms as well. Hence, light therapy might not only be effective for depressive symptoms and circadian rhythms, but might also be beneficial for symptoms including inattention and irritability. We hypothesize that light therapy might be a helpful adjunctive treatment enhancing affective and circadian functioning, and eliciting positive influences on behavior. Physiologically, changes of both cortisol levels and melatonin production are expected.

Pediatric insomnia

Bedtime struggles, delayed sleep onset, and problematic night wakings are extremely common in the pediatric population, and have a significant impact on quality of life of both children and caregivers. This article reviews the research and clinical nosology of childhood insomnia, prevalence, and etiologic factors in infants, children, and adolescents. Clinical presentation, evaluation, and treatment, both behavioral and pharmacologic, of the most common types of pediatric insomnia are presented. Insomnia in special populations, particularly children with chronic medical, psychiatric, and neurodevelopmental disorders, is discussed. Future directions in childhood insomnia are presented.

Sleep problems in children and adolescents with common medical conditions

Untreated sleep disturbances and sleep disorders pose significant adverse daytime consequences and place children at considerable risk for poor health outcomes. Sleep disturbances occur at a greater frequency in children with acute and chronic medical conditions compared with otherwise healthy peers. Sleep disturbances in medically ill children can be associated with sleep disorders, comorbid with acute and chronic conditions, or secondary to underlying disease-related mechanisms, treatment regimens, or hospitalization. Clinical management should include a multidisciplinary approach with particular emphasis on routine, regular sleep assessments and prevention of daytime consequences, and promotion of healthy sleep habits and health outcomes.

The developmental impact of prenatal stress, prenatal dexamethasone and postnatal social stress on physiology, behaviour and neuroanatomy of primate offspring: studies in rhesus macaque and common marmoset

RATIONALE

Exposure of the immature mammalian brain to stress factors, including stress levels of glucocorticoids, either prenatally or postnatally, is regarded as a major regulatory factor in short- and long-term brain function and, in human, as a major aetiological factor in neuropsychiatric disorders. Experimental human studies are not feasible and animal studies are required to demonstrate causality and elucidate mechanisms. A number of studies have been conducted and reviewed in rodents but there are relatively few studies in primates.

OBJECTIVES

Here we present an overview of our published studies and some original data on the effects of: (1) prenatal stress on hypothalamic-pituitary-adrenal (HPA) re/activity and hippocampus neuroanatomy in juvenile-adolescent rhesus macaques; (2) prenatal dexamethasone (DEX) on HPA activity, behaviour and prefrontal cortex neuroanatomy in infant-adolescent common marmosets; (3) postnatal daily parental separation stress on HPA re/activity, behaviour, sleep and hippocampus and prefrontal cortex neuroanatomy in infant-adolescent common marmoset.

RESULTS

Prenatal stress increased basal cortisol levels and reduced neurogenesis in macaque. Prenatal DEX was without effect on HPA activity and reduced social play and skilled motor behaviour in marmoset. Postnatal social stress increased basal cortisol levels, reduced social play, increased awakening and reduced hippocampal glucocorticoid and mineralocorticoid receptor expression in marmoset.

CONCLUSIONS

Perinatal stress-related environmental events exert short- and long-term effects on HPA function, behaviour and brain status in rhesus macaque and common marmoset. The mechanisms mediating the enduring effects remain to be elucidated, with candidates including increased basal HPA function and epigenetic programming.

Adolescent sleep, risk behaviors, and depressive symptoms: are they linked?

OBJECTIVE

To explore how weekday and weekend sleep patterns are related to adolescent substance use, depressive symptoms, and school truancy.

METHODS

Selfreport surveys of 242 youth (93.4% white, mean age 16.4 years).

RESULTS

Longer weekday sleep duration was inversely associated with depressive symptoms, past month alcohol use, and drunkenness. Later weekend bedtime and wake-times, compared to those of weekdays, were associated with increased substance use and truancy.

CONCLUSIONS

Weekday sleep duration appears to be protective for substance use, depression and school truancy for teenagers. However, inconsistent sleep patterns between weekdays and weekends were associated with a range of markers for adolescent risk.

Classification and epidemiology of sleep disorders

Sleep disturbances are common in children and adolescents but still remain underrecognized and undertreated. Several classification systems of sleep disorders are available, including some newer attempts to develop more specific nosologic categories that reflect developmental aspects of sleep. The prevalence of sleep disorders has been studied across various samples of healthy, normal children and in children with special medical and neurodevelopmental needs. Sleep disorders are more frequently seen in children and adolescents with psychiatric disorders, making it very important for mental health professionals to be aware of sleep problems and to address them in the context of psychiatric comorbidities.

The adverse consequences of sleep disturbance in pediatric bipolar disorder: implications for intervention

Bipolar disorder (BPD) is a severe and chronic disorder, ranked among the top 10 leading causes of disability worldwide. Bipolar spectrum disorders with onset in childhood and adolescence have a particularly severe course, including more suicide attempts and greater comorbidity. The evidence accrued to date indicates that sleep disturbances are common among youth with BPD. Moreover, sleep problems may be an early marker for BPD, a distinguishing feature of BPD, and a contributor to relapse. The evidence reviewed highlights that sleep problems are associated with a range of serious adverse consequences, including difficulty in regulating affect in the daytime and difficulties with cognitive functions, such as memory, learning, attention, and concentration. Evidence reviewed also points to sleep disturbance as one possible contributor to weight gain, comorbid substance use, and impulsivity. The implications for intervention are explored, and a multicomponent sleep intervention for youth with BPD is outlined.

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.

Objective sleep in pediatric anxiety disorders and major depressive disorder

OBJECTIVE

To examine objective and subjective sleep problems in early-onset anxiety and depression.

METHOD

Children and adolescents (46% female, ages 7 to 17 years) with anxiety disorders (n = 24), major depressive disorder (MDD) without comorbid anxiety disorders (n = 128), or no history of psychiatric disorder (n = 101) spent two consecutive nights in a sleep laboratory and completed self-reports of sleep quality.

RESULTS

On objective measures, the anxiety group exhibited more awakenings than the MDD group, less slow-wave sleep than the control or MDD group, and greater night 2 sleep latency than the MDD or control group. The anxiety group exhibited no decrease in rapid eye movement latency from the first night to the second. The MDD group exhibited less time awake than the control group and less stage 1 sleep than the anxiety or control group. On subjective measures, young people with anxiety reported greater sleep latency on the second night and no decrease in sleep latency. Age was covaried in analyses.

CONCLUSIONS

Findings provide objective and subjective evidence of sleep disturbance in children and adolescents with anxiety disorders and replicate findings of limited objective sleep disturbance in those with MDD. Sleep problems are an important consideration when treating young people with anxiety.

Caffeine consumption, sleep, and affect in the natural environments of depressed youth and healthy controls

OBJECTIVE

Sleep problems are a cardinal symptom of depression in children and adolescents and caffeine use is a prevalent and problematic issue in youth; yet little is known about caffeine use and its effects on sleep in youth with depression. We examined caffeine use and its relation to sleep and affect in youth's natural environments.

METHODS

Thirty youth with major depressive disorder (MDD) and 23 control youth reported on caffeine use, sleep, and affect in their natural environment using ecological momentary assessment at baseline and over 8 weeks, while MDD youth received treatment.

RESULTS

Youth with MDD reported more caffeine use and sleep problems relative to healthy youth. Youth with MDD reported more anxiety on days they consumed caffeine. Caffeine use among youth with MDD decreased across treatment, but sleep complaints remained elevated.

CONCLUSIONS

Findings suggest that both sleep quality and caffeine use are altered in pediatric depression; that caffeine use, but not sleep problems, improves with treatment; and that caffeine may exacerbate daily anxiety among youth with depression.

Social neuroscience of child and adolescent depression

The social neuroscience of child and adolescent depression is inherently multidisciplinary. Depressive disorders beginning early in life can have serious developmental and functional consequences. Psychopathology research has described depression's defining clinical and contextual features, and intervention research has characterized its response to treatment and prevention programs. Neuroendocrine, electrophysiological, and neuroimaging studies have identified core neurobiological aspects of early-onset mood disorders. These areas are reviewed using a developmental social neuroscience perspective for integrating disparate observations. The paper introduces a dynamic adaptive systems framework, and it discusses hedonic capacity, stress sensitivity, ruminative self-focus, and attentional impairments as fundamental components of mood disorders.

Sleepless in America: inadequate sleep and relationships to health and well-being of our nation's children

OBJECTIVE

Our goal was to identify characteristics associated with inadequate sleep for a national random sample of elementary school-aged children (6-11 years) and adolescents (12-17 years).

METHODS

Data from 68418 participants in the 2003 National Survey of Children's Health were analyzed by using weighted bivariate and multivariate regression models. The dependent variable was report of not getting enough sleep for a child of his or her age >or=1 night of the past week. Independent variables included demographic characteristics, child health, school and other activities, and family life.

RESULTS

Parents of elementary school-aged children with inadequate sleep were more likely to report that their child was having problems at school or had a father with fair or poor health. Parents of adolescents with inadequate sleep were more likely to report that their child had an atopic condition, frequent or severe headaches, a parent with less-than-excellent emotional health, or experienced frequent parental anger. Inadequate sleep in both age groups was associated with parental report that their child usually or always displayed depressive symptomatology, family disagreements involved heated arguing, or parental concern that the child was not always safe at home, at school, or in their neighborhood.

CONCLUSIONS

Approximately 15 million American children are affected by inadequate sleep. Primary care providers should routinely identify and address inadequate sleep and its associated health, school, and family factors.

Neurobiology of depression in children and adolescents

This article reviews classical and updated studies of the neurobiology of depressive disorders in children and adolescents. Most studies of childhood and adolescent depression and suicide have followed up the observations and methods used in studies in adults. These studies include neuroendocrine studies, which particularly look at the hypothalamic-pituitary-adrenal axis, the serotonergic system, peripheral blood and cerebrospinal fluid biologic markers, genetics, gene-environment interactions and sleep studies, and neuroimaging and postmortem studies, although in these areas the number of studies is limited.

Peri-sleep-onset cortisol levels in children and adolescents with affective disorders

BACKGROUND

Changes in the hypothalamic-pituitary-adrenal (HPA) axis, as evidenced by patterns of cortisol secretion, have been of interest in understanding depression and anxiety disorders across the life span. Previous studies of pediatric depression have pointed to the period around sleep onset as a key time point for observing alterations in cortisol secretion associated with affective disorders. Evidence also indicates that pubertal development may influence the expression of HPA dysregulation. We hypothesized that adolescents with depression and youth with anxiety disorders exhibit elevated peri-sleep-onset cortisol.

METHODS

Plasma cortisol was sampled every 20 min around sleep onset from children and adolescents with major depressive disorder (n = 116), anxiety disorders (n = 32), or no history of psychiatric disorder (control; n = 76). Sleep onset was determined by polysomnography. Classification of participants as children or adolescents was based on Tanner staging of pubertal maturation.

RESULTS

Children with anxiety disorders had higher peri-sleep-onset cortisol than children with depression or control children. Adolescents with depression had marginally higher peri-sleep-onset cortisol than control adolescents and significantly higher peri-sleep-onset cortisol than children with depression.

CONCLUSIONS

Depression and anxiety are associated with altered cortisol secretion around sleep onset, and these changes appear to be influenced by pubertal maturation.

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.

Subjective sleep complaints in pediatric depression: a controlled study and comparison with EEG measures of sleep and waking

OBJECTIVE

Children with major depressive disorder (MDD) often complain of sleep disturbances; however, polysomnographic studies have failed to find objective evidence of these disturbances. This article examines subjective sleep reports of children with MDD and healthy controls focusing on comparing subjective and objective sleep measures.

METHOD

Fifty-one subjects with MDD and 42 healthy subjects, 8-17 years old, participated in a comprehensive psychobiologic study including three nights of EEG sleep recording. Each morning, subjects completed a post-sleep form subjectively rating their sleep, which was then compared with their polysomnographic studies.

RESULTS

Depressed subjects reported significantly worse sleep on four scales: subjective sleep quality, perceived number of awakenings, estimated minutes awake, and perceived ease of waking. In contrast to these subjective complaints, objective EEG measures indicated no evidence of disturbed sleep in the depressed sample compared to controls. Furthermore, exploratory analyses focusing on the subset of depressed subjects with the greatest subjective sleep disturbance showed, paradoxically, significantly better sleep in terms of the number of EEG awakenings and objective disturbances.

CONCLUSIONS

Despite clinical evidence of subjective sleep complaints in depressed children, our EEG measures showed little evidence to indicate an objective basis for these perceptions. These findings raise provocative questions regarding the nature of sleep complaints associated with early-onset depression.

The ADHD and sleep conundrum: a review

The relationship between attention-deficit hyperactivity disorder (ADHD) and sleep is a complex one that poses many challenges in clinical practice. Recent studies have helped to elucidate the nature of the brain mechanisms and neuromodulator systems underlying the theoretical associations among sleepiness, arousal, and attention. Studies of sleep disturbances in children with academic and behavioral problems have also underscored the role that primary sleep disorders such as obstructive sleep apnea hypopnea syndrome play in the clinical presentation of symptoms of inattention and behavioral dysregulation. In addition, new methodologies used in examining sleep and sleep patterns in children diagnosed with ADHD have shed further light on the prevalence, type, risk factors for, and impact of sleep disturbances in these children. The following discussion of the multilevel relationships among sleep quality and quantity, neurobehavioral functioning, and the clinical syndrome of ADHD expands on previous reviews of the literature and synthesizes what is currently known about the interaction of sleep and attention/arousal in children to propose possible underlying mechanisms, integrate more recent findings, and highlight important areas for future study. In addition, guidelines are provided for a clinical approach to evaluation and management of children with ADHD and sleep problems.

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.