Dexamethasone suppression test in children with major depressive disorder

In search of HPA axis dysregulation in child and adolescent depression

Dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis in adults with major depressive disorder is among the most consistent and robust biological findings in psychiatry. Given the importance of the adolescent transition to the development and recurrence of depressive phenomena over the lifespan, it is important to have an integrative perspective on research investigating the various components of HPA axis functioning among depressed young people. The present narrative review synthesizes evidence from the following five categories of studies conducted with children and adolescents: (1) those examining the HPA system’s response to the dexamethasone suppression test (DST); (2) those assessing basal HPA axis functioning; (3) those administering corticotropin-releasing hormone (CRH) challenge; (4) those incorporating psychological probes of the HPA axis; and (5) those examining HPA axis functioning in children of depressed mothers. Evidence is generally consistent with models of developmental psychopathology that hypothesize that atypical HPA axis functioning precedes the emergence of clinical levels of depression and that the HPA axis becomes increasingly dysregulated from child to adult manifestations of depression. Multidisciplinary approaches and longitudinal research designs that extend across development are needed to more clearly and usefully elucidate the role of the HPA axis in depression.

Behavioral adjustment in a community sample of boys: links with basal and stress-induced salivary cortisol concentrations

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been observed in association with internalizing symptoms and is thought to be involved in the pathogenesis of depression and some anxiety disorders. This study examined basal and stress-induced cortisol concentrations in relation to internalizing and externalizing symptoms in a racially mixed community sample of 102 8-11-year-old boys. Afternoon basal cortisol concentrations were positively correlated with measures of internalizing behavior problems, social problems, and emotionality. Greater change in cortisol across a home-visit challenge task was also significantly associated with internalizing behaviors and social problems, as well as attention and thought problems. The implications of these findings and how they may relate to the pathogenesis of emotional and behavioral problems are discussed.

A critical review of the empirical literature on the relation between anxiety and puberty

The current paper critically reviews the empirical literature focused on the association between puberty and anxiety. A detailed review of more than 45 empirical articles is provided. There is some evidence that among girls, but not boys, a more advanced pubertal status (controlling for age) is associated with higher reported anxiety symptoms. Also among girls, earlier pubertal timing is linked to higher anxiety scores. It is unclear whether early puberty may lead to increased anxiety or if high anxiety influences pubertal timing. With respect to hormones, there were relatively few significant associations for girls, although this literature is very small. Among boys, several studies reported positive associations between both gonadal and adrenal hormones and anxiety. The direction of effect for these finding is also unstudied. The primary limitation of the hormone-anxiety literature pertains to the absence of pubertal measures in samples of youth in which hormones are measured. The paper concludes with a comprehensive examination of the methodological strengths and weaknesses of the literature and recommendations for future work.

Emanuel Miller Lecture: early onset depressions--meanings, mechanisms and processes

BACKGROUND

Depressive syndromes in children and adolescents constitute a serious group of mental disorders with considerable risk for recurrence. A more precise understanding of aetiology is necessary to improve treatment and management.

METHODS

Three neuroactive agents are purported to be involved in the aetiology of these disorders: serotonin, brain-derived neurotrophic factor and cortisol. A literature review was conducted to determine their contributions to the emergence of unipolar depressions in the adolescent years.

RESULTS

Serotonin, brain-derived neurotrophic factor and cortisol may operate in concert within two distinct functional frameworks: atypical early epigenesis arising in the first few years of life and resulting in the formation of a vulnerable neuronal network involving in particular the amygdala and ventral prefrontal cortex. Individuals with this vulnerability are likely to show impaired mood regulation when faced with environmental demands during adolescence and over the subsequent decades; and acquired neuroendangerment, a pathological brain process leading to reduced synaptic plasticity, in particular in the hippocampus and perhaps the nucleus accumbens and ventral tegmentum. This may result in motivational, cognitive and behavioural deficits at any point in the lifespan most apparent at times of environmental demand.

CONCLUSIONS

The characteristics, course and outcome of a depressive episode may depend on the extent of the involvement of both atypical early neurogenesis and acquired neuroendangerment.

Antidepressants in child and adolescent depression: where are the bugs?

OBJECTIVE

To examine the data on the effect of antidepressant medication in depressed children and adolescents and the causes of the results obtained.

METHOD

A systematic literature search was conducted, supplemented by a manual search, and a search of public online information on paediatric antidepressant trials reviewed by regulatory agencies.

RESULTS

Data gathered from published and unpublished randomized controlled trials vary in their findings, with most of the studies showing a lack of efficacy characterized by a high placebo response rate.

CONCLUSION

Differences from efficacy results with the same drugs in adult depression may be because of neurobiological developmental correlates, developmental differences in pharmacokinetics and pharmacodynamics, high rates of placebo response in children, and a number of methodological influences. There are several areas needing more attention in paediatric antidepressant clinical trials. Judicious use of published and unpublished studies to assess who may benefit from treatment with antidepressants seems warranted.

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.

Child maltreatment and HPA axis dysregulation: relationship to major depressive disorder and post traumatic stress disorder in females

A history of child maltreatment increases the vulnerability to the development of Major Depressive Disorder (MDD) and/or Posttraumatic Stress Disorder (PTSD), especially in females. Both MDD and PTSD are associated with a dysregulation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. Dysregulation of the HPA axis may be an important etiological link between child maltreatment and subsequent psychiatric disorder, yet little is known about the relationship between exposure and outcome. The aim of this review is to explore the role of HPA axis dysregulation in the link between child maltreatment and MDD/PTSD among women. Studies of females with MDD frequently indicate a hyperactivity of the HPA axis, and contribute to our understanding of the underlying mechanisms involved in mood dysregulation. Evidence for HPA axis dysregulation in PTSD is less convincing and suggests that timing of the stressful experience as well as the type of the trauma may influence the outcome. The strongest evidence to date suggesting that the development of the HPA axis may be affected by early life stressful experiences comes from pre-clinical animal studies. Together these studies add to our understanding of the role of the HPA axis in psychiatric disorders in relation to stress. The literature on HPA axis function in both children and adults following child maltreatment further highlights the potential relevance of early stress to later onset of major psychiatric disorders. Such knowledge may also contribute to the development of early interventions targeted at primary prevention.

Twenty-four-hour cortisol secretion patterns in prepubertal children with anxiety or depressive disorders

BACKGROUND

Previous studies found few abnormalities in hypothalamic-pituitary-adrenal (HPA) axis function in prepubertal children with anxiety or depressive disorders. In this study, we combined data from two independent, consecutive studies to achieve a larger sample size. Our goal was to identify potential alterations in the circadian pattern of cortisol secretion in anxious or depressed children.

METHODS

A total of 124 prepubertal subjects from two independent samples (76 with major depressive disorder, 31 with anxiety disorders, and 17 healthy control subjects) were studied. Blood samples collected for cortisol at hourly intervals over a 24-hour period were examined. Analyses were performed aligning cortisol samples by clock-time. Additional analyses aligning samples by sleep-onset time were performed with a subsample of subjects.

RESULTS

In the combined sample, significant findings emerged that were previously undetected. Anxious children exhibited significantly lower nighttime cortisol levels and an initially sluggish rise in cortisol during the nighttime when compared with depressed and healthy control children. In contrast, depressed children did not show a clear-cut pattern of differences compared with healthy control children.

CONCLUSIONS

Anxious children seem to exhibit an altered pattern of nighttime cortisol secretion, with an initially sluggish or delayed nocturnal rise before reaching similar peak levels of cortisol near the time of awakening. These findings suggest subtle alterations in HPA axis function in prepubertal children with anxiety disorders.

Possible role of cortisol and dehydroepiandrosterone in human development and psychopathology

BACKGROUND

The characteristics of adrenal hormone secretion change markedly during infancy. Disturbances in basal levels may precipitate psychological dysfunction and are associated with psychopathology in young people.

AIMS

To relate three aspects of behavioural endocrinology: developmental changes in cortisol and dehydroepiandrosterone (DHEA), the role of these hormones in the psychopathology of young people, and the action of these steroids in the brain.

METHOD

A selective review from the human developmental, psychiatric and neurosciences literature.

RESULTS

There are developmentally mediated changes in brain sensitivity following excess exposure to cortisol. This may result in impairments of mental and behavioural function. DHEA and gonadal steroids may modulate the actions of cortisol.

CONCLUSIONS

Steroid hormones contribute to shaping behavioural function during early development and act as risk factors for psychopathology.

Are child-, adolescent-, and adult-onset depression one and the same disorder?

This paper reviews prior research studies examining neurobiological correlates and treatment response of depression in children, adolescents, and adults. Although there are some similarities in research findings observed across the life cycle, both children and adolescents have been found to differ from depressed adults on measures of basal cortisol secretion, corticotropin stimulation post-corticotropin releasing hormone (CRH) infusion, response to several serotonergic probes, immunity indices, and efficacy of tricyclic medications. These differences are proposed to be due to 1) developmental factors, 2) stage of illness factors (e.g., number of episodes, total duration of illness), or 3) heterogeneity in clinical outcome (e.g., recurrent unipolar course vs. new-onset bipolar disorder). Relevant clinical and preclinical studies that provide support for these alternate explanations of the discrepant findings are reviewed, and directions for future research are discussed. To determine whether child-, adolescent-, and adult-onset depression represent the same condition, it is recommended that researchers 1) use the same neuroimaging paradigms in child, adolescent, and adult depressed cohorts; 2) carefully characterize subjects' stage of illness; and 3) conduct longitudinal clinical and repeat neurobiological assessments of patients of different ages at various stages of illness. In addition, careful attention to familial subtypes (e.g., depressive spectrum disorders vs. familial pure depressive disorders) and environmental factors (e.g., trauma history) are suggested for future investigations.

Prolactin secretion in depressed children

BACKGROUND

Few studies have examined the involvement of the central dopaminergic system in the pathophysiology of mood disorders. The study of prolactin (PRL) secretion may be an informative indirect method for the assessment of the dopaminergic system in children with major depressive disorder (MDD).

METHODS

Plasma PRL concentrations were measured at 20-min intervals over a 24-hr period in 40 pre-pubertal children with MDD, 18 with non-affective psychiatric disorders (PC), and 6 normal controls (NC). A subgroup of depressed children (n = 21) was restudied after recovery.

RESULTS

There was no significant differences in either the amount or the pattern of PRL secretion between the MDD, PC, and NC groups. Children who recovered from their depression secreted less PRL during sleep and more while awake compared to when they were acutely depressed.

CONCLUSIONS

Overall, there were no differences in baseline PRL secretion between children with MDD, NC and psychiatric control. These results suggest that the dopaminergic system as measured by baseline PRL blood levels is not compromised in children with MDD.

Psychoneuroendocrinology of children and adolescents

This article reviews psychoneuroendocrinologic approaches to the understanding of internalizing disorders (depression and anxiety disorders) and externalizing disorders. This article discusses three specific psychoneuroendocrine systems: measures of the hypothalamic-pituitary-adrenal (HPA) axis, measure of the serotonergic function, and measures of the growth-hormone (GH) response to pharmacologic challenge. The hypothalamic-pituitary-adrenal (HPA) axis is the main system; understanding this system may reveal information on the permissive and etiologic relationship of stress to psychiatric disorder.

Laboratory and diagnostic testing in child and adolescent psychiatry: a review of the past 10 years

OBJECTIVE

To review in a critical fashion the literature of the past decade covering diagnostic and laboratory testing in the field of child and adolescent psychiatry.

METHOD

A computerized search of articles published during the past decade was made, and selected articles are presented. Because of the paucity of articles specifically relating to minors, selected articles from adult psychiatry are cited.

RESULTS

With a few notable exceptions, few controlled studies on the specificity and sensitivity of any laboratory test for any specific disorder of behavior presenting in children have been conducted in children and adolescents. A high index of suspicion will remain the clinician's best ally in utilizing laboratory measures in the assessment of psychopathology. Nonetheless, studies have appeared that will guide the clinician as to what tests are not clinically useful.

CONCLUSION

Indications and the lack of indications for specific laboratory studies are an integral part of the knowledge base that child psychiatrists must have. Much more empirical data will need to be collected prospectively to inform the field and to move the judicious use of the laboratory from an art to a science.

Differential effects of hydrocortisone and dexamethasone on cortisol suppression in a child psychiatric population

The suppressive effect of hydrocortisone and dexamethasone on salivary cortisol was investigated in a 2-year study of pituitary-adrenal function in a variety of child psychiatric patients and healthy controls. Symptomatology was assessed using the Child Behavioral Checklist (CBCL). Cortisol day profiles were assessed at 2-h intervals from 0800 to 2000 h on three occasions. Dexamethasone and hydrocortisone were administered orally twice at 2000 h, the doses being adjusted for bodyweight according to the standard dexamethasone suppression test. Fifty-one patients, including patients with dysthymia, oppositional defiant disorder, pervasive developmental disorder, and attention deficit hyperactivity disorder, and ten age and sex matched controls participated. Basal cortisol levels in patients were generally lower than in controls. Both dexamethasone and hydrocortisone were effective in suppressing salivary cortisol, although dexamethasone was somewhat more potent and its effect lasted longer. Hyporesponsiveness to hydrocortisone, but not to dexamethasone, distinguished patients with dysthymia and oppositional defiant disorder from controls. Responsiveness to hydrocortisone was correlated with the symptom clusters social problems and anxious/depressed. The data support the idea that there exist syndrome aspecific disturbances in feedback activity beyond the level of the pituitary, i.e. at the hypothalamic level, at an early age. From this perspective, hydrocortisone suppression is a useful tool for studying pituitary-adrenal function in children. Behavioral correlates of these disturbances of pituitary-adrenal function should be determined.

Childhood and adolescent depression: a review of the past 10 years. Part I

OBJECTIVE

To qualitatively review the literature of the past decade covering the epidemiology, clinical characteristics, natural course, biology, and other correlates of early-onset major depressive disorder (MDD) and dysthymic disorder (DD).

METHOD

A computerized search for articles published during the past 10 years was made and selected studies are presented.

RESULTS

Early-onset MDD and DD are frequent, recurrent, and familial disorders that tend to continue into adulthood, and they are frequently accompanied by other psychiatric disorders. These disorders are usually associated with poor psychosocial and academic outcome and increased risk for substance abuse, bipolar disorder, and suicide. In addition, DD increases the risk for MDD. There is a secular increase in the prevalence of MDD, and it appears that MDD is occurring at an earlier age in successive cohorts. Several genetic, familial, demographic, psychosocial, cognitive, and biological correlates of onset and course of early-onset depression have been identified. Few studies, however, have examined the combined effects of these correlates.

CONCLUSIONS

Considerable advances have been made in our knowledge of early-onset depression. Nevertheless, further research is needed in understanding the pathogenesis of childhood mood disorders. Toward this end, studies aimed at elucidating mechanisms and interrelationships among the different domains of risk factors are needed.

Changes in thyroid hormone levels associated with desipramine response in adolescent depression

1. The authors recently reported that acutely ill depressed adolescents have elevated plasma T4 and fT4 compared to controls. Studies in adult depression suggest antidepressant response is associated with decreases in these elevated levels. The effect of antidepressant treatment on adolescent thyroid indices has not been examined. 2. Thyroid indices were examined in 12 adolescent patients (4 male, 8 female; age 14-19y) in the active treatment arm of a double-blind, placebo-controlled desipramine trial (200 mg/day for 6 weeks). Antidepressant responders had higher pre-treatment levels of T4 and larger decreases were observed responders vs. nonresponders. 3. These results replicate findings observed in adult depressed patients and suggest similar alterations in the hypothalamic-pituitary-thyroid (HPT) axis function in adolescent depression.

Adrenal secretion during major depression in 8- to 16-year-olds, I. Altered diurnal rhythms in salivary cortisol and dehydroepiandrosterone (DHEA) at presentation

The association between basal cortisol, dehydroepiandrosterone (DHEA), its sulphate (DHEAS) and major depression was investigated in 8- to 16-year-olds. Eighty-two subjects with major depression, 25 non-depressed psychiatric cases and 40 community controls were systematically assessed for current mental state and hormone levels at 08.00, 12.00 and 20.00 h, assayed from salivary samples collected over a 48 h period. The average mean of the two time points was compared between the three groups. Evening cortisol hypersecretion and morning DHEA hyposecretion were significantly, and independently, associated with major depression. High evening cortisol (> 0.594 ng/mL) and low morning DHEA (< 0.200 ng/mL) identified subgroups of depressives with different types of adrenal hormone dysregulation. The association between high evening cortisol or low morning DHEA and MDD was not affected by either age or gender.

Corticotropin-releasing hormone challenge in prepubertal major depression

This study investigates cortisol and ACTH (corticotropin) responses to an infusion of human CRH (corticotropin-releasing hormone) in prepubertal children with major depressive disorder (MDD). Following a period of 24 hours of adaptation to the laboratory environment with an intravenous catheter in place, 34 children with MDD and 22 healthy controls received 1 microgram/kg of human CRH at 5:00 PM. Blood samples for cortisol and ACTH were measured at baseline and post-CRH. Overall, there were no significant differences between the MDD and the normal controls in baseline or post CRH stimulation values of either cortisol or ACTH. Melancholic (n = 4) patients had significantly higher baseline cortisol levels than nonmelancholic (n = 24) patients. Compared with the outpatients and the nonmelancholics, the inpatients (n = 10) and the melancholics showed significantly lower total ACTH secretion (effect size: 0.9 and 1.4, respectively) after CRH infusion. These results are consistent with a broad literature suggesting that the HPA axis abnormalities occur less frequently in early-onset depression than reported in adult studies. The pattern of results in the subgroups of inpatients and in melancholic children, however, raise questions about possible continuities with adult studies.

Salivary testosterone and cortisol in disruptive children: relationship to aggressive, hyperactive, and internalizing behaviors

OBJECTIVE

To test predictions that basal salivary testosterone and cortisol are related to antisocial and internalizing behaviors, respectively, and that cortisol moderates the testosterone-aggression relationship.

METHOD

Saliva samples were assayed to determine testosterone and cortisol levels in 40 clinic-referred disruptive children (aged 7 through 14 years) who were rated on aggression, inattention/overactivity, and internalizing behavior by parents, teachers, and clinic staff members.

RESULTS

Results indicated significant positive relationships between testosterone and staff-rated aggression and between cortisol and parent-rated internalizing behavior. A significant negative relationship was found between cortisol and staff-rated inattention/overactivity. No interactions between testosterone and cortisol were found. These results were maintained regardless of age, racial background, height, weight, diagnosis, or medication status.

CONCLUSIONS

Results suggest moderate relationships between testosterone and observed aggression, and between cortisol and emotional behaviors, in a group of disruptive children. Cortisol did not moderate the testosterone-aggression relationship in this population.

Basal thyroid indices in adolescent depression and bipolar disorder

OBJECTIVE

Abnormalities of the thyroid axis are documented in adult mood disorders. The most consistent findings have been observed in major depressive disorder with elevations of thyroxine (T4) or free-T4 (fT4) within the euthyroid range that decrease with treatment. The literature on adolescents is limited, and it is unknown whether similar findings might be present in this population.

METHOD

First admissions to a university hospital adolescent psychiatry unit were reviewed. Fourteen depressed and 13 manic patients satisfied inclusion and exclusion criteria. None had a history of thyroid illness or medical illness or were taking medications known to affect thyroid function. Basal serum thyrotropin, T4, fT4, triiodothyronine (T3), reverse-T3, free thyroxine index (FTI), and T3 resin uptake levels were compared with those of a group of adolescent normal controls.

RESULTS

T4 (but not fT4) was elevated in depressed and manic patients compared with controls (p < .05). In manic patients, T3 was decreased and reverse-T3 was increased (p < .05). There were no significant differences in relation to age, sex, or suicidality.

CONCLUSIONS

We observed significant differences in basal thyroid hormone levels in depressed and manic adolescents. Our results suggest the presence of abnormalities of thyroid function in adolescent mood disorders similar to those described in mood-disordered adults.

The dexamethasone suppression test in children and adolescents: a review and a controlled study

Dexamethasone Suppression Test (DST) studies conducted in children and adolescents are reviewed, together with factors hypothesized to explain discrepancies in rates of DST nonsuppression across studies. These factors are then examined in a controlled study of 27 adolescents with major depressive disorder (MDD) and 34 normal controls (NC). Subjects were given 1 mg of dexamethasone at 11:00 PM, and the following day serum samples for cortisol were collected each hr from 8 AM to 11 PM through an indwelling catheter. There were no significant differences found between the MDD and NC subjects on any postdexamethasone cortisol measure. Further, cortisol suppressors and nonsuppressors were not distinguished by any of the hypothesized factors identified from the review, including inpatient status, presence of suicidality, endogenous features, psychotic symptoms, or prior history of MDD. Questions about the appropriateness of the 1 mg dose of dexamethasone (currently the standard dose used with adolescents) are raised, together with a discussion of the effects of stress on DST findings.

Regulation of sleep and growth hormone in adolescent depression

This article reviews findings of sleep, growth hormone (GH), and cortisol measures from a number of separate controlled studies of prepubertal and adolescent depression carried out by Puig-Antich and colleagues since 1978. New data are presented comparing 24-hour GH measures in adolescents with major depressive disorder (MDD) (N = 44; mean age = 14.8 +/- 2.0) to normal control adolescents (N = 37; mean age = 15.3 +/- 1.5). There were no significant overall group differences in summary GH measures between MDD and normal controls. Splitting the MDD group on the basis of suicidality (definite plan or attempt) (N = 20), revealed a significant blunting of sleep GH compared to the nonsuicidal group (N = 24). These results are discussed in the context of the other sleep and neuroendocrine findings in this population, with evidence for dysregulation around sleep onset. The influences of development on sleep and GH regulation are also considered.