Use of the dexamethasone suppression test with DSM-III criteria in psychiatrically hospitalized adolescents

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.

5HT1A-mediated stimulation of cortisol release in major depression: use of non-invasive cortisol measurements to predict clinical response

The purpose of the present study was to explore 5HT1A-mediated cortisol release in major depressive disorder (MDD) patients in order to determine whether the degree of 5HT1A-receptor sensitivity can predict response to treatment with selective serotonin reuptake inhibitors (SSRIs). We examined whether the sensitivity of the 5HT1A receptor, as measured by the difference in salivary cortisol levels immediately before and 90 min following the administration of a single dose of the 5HT1A-selective agonist buspirone, predicted treatment outcome following an 8-week, fixed-dose, open trial of the SSRI escitalopram in 17 outpatients with MDD. Change in cortisol levels before and 90 min after the administration of buspirone were not found to predict treatment outcome, whether defined as clinical response (50% or greater reduction in symptom severity), or remission of symptoms. In conclusion, in the present study, we did not find that the change in salivary cortisol levels following the administration of a 5HT1A-selective agonist predicted treatment outcome following an 8-week, fixed-dose, open-label trial of the SSRI escitalopram among outpatients with MDD. Although the 5HT1A-desensitization hypothesis is still a valid one, the results of the present study could not provide any evidence in support.

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.

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.

Measurement of cortisol and lymphocyte subpopulations in depressed and conduct-disordered adolescents

Lymphocyte subpopulations were analyzed in 11 adolescents with major depressive disorder, 11 with conduct disorder, and eight normal age-matched subjects. No significant differences were noted on any T or B cell measure between the groups. Further, no significant correlations were found between any cortisol measure (baseline cortisol, post-dexamethasone cortisol, urinary free cortisol) and any lymphocyte measure in either depressed or conduct-disordered adolescents. The negative findings in this small sample contrast with those reported in adult patients and suggest that an aging effect may be associated with the immunological changes reported in older depressed patients.

Neuroendocrine investigation in children and adolescents with dysthymic disorders: the DST, TRH and clonidine tests

A neuroendocrine study was conducted in eight children and adolescents with dysthymic disorders (three females and five males) and in eight age- and sex-matched psychologically normal controls. The dexamethasone suppression test (DST), TSH and GH responses to TRH stimulation and GH response to clonidine stimulation were studied in parallel in each patient. Depressive symptomatology was monitored with the Poznanski Rating Scale. The DST, TRH and clonidine tests revealed normal responses in each patient. TRH induced abnormal GH rises in five of the eight patients. There were no correlations between neuroendocrine parameters and degree of depression, age, sex or weight of the patients, age of onset, duration and family history of the disease.

Noradrenergic function and hypothalamic-pituitary-adrenal axis activity in adolescents with major depressive disorder

Levels of plasma norepinephrine (NE), free 3-methoxy-4-hydroxyphenylglycol (MHPG), and cortisol in adolescents with major depressive disorder (10 girls, 1 boy; mean +/- SD age = 16.4 +/- 1.6 years, range = 14-19 years) did not differ significantly from those in a group of healthy adolescents (17 girls, 12 boys; mean +/- SD age = 15.9 +/- 1.5 years, range = 12-18 years). No correlations were observed between these variables and age within the adolescent groups. However, when the adolescent data were viewed in combination with data previously obtained for an adult population (De Villiers et al., 1987), significant positive correlations between the variables were observed within the patient group. A moderate positive correlation with age was also observed for patients' NE and free MHPG levels. No such correlations were observed for the combined control group. When groups were partitioned into three age categories, it became apparent that differences in the three variables between the patient and the control groups were restricted to elderly subjects (greater than 50 years). In adults (21-50 years old), only the patients' NE levels were significantly elevated. These findings suggest that duration of illness may be important in determining the full expression of the biochemical abnormality in major depression.