Biochemical profile of depressed 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.

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.

Pediatric depression and psychopharmacology

Children can and do have depression which is similar to and continuous with that in adults. It can be diagnosed and treated similarly. Clinical evaluation reveals depression and laboratory tests are not required. It may be comorbid with other psychiatric or physical disorders. It causes considerable distress and impairment and suicide can be one serious sequel. Relapse or recurrences can occur. Etiology of depression is uncertain though hypotheses of psychogenesis or biogenesis exists. Psycho-pharmacological advances have helped in understanding etiology of depression and also in its effective treatment. So far, fluoxetine in the only antidepressant shown to be effective though others are also used. Antidepressants need to be given for one year or more.

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.

The failure of 'adult' interventions with adolescent depression: what does it mean for theory, research and practice?

The literature on the biological and phenomenologic presentation of major depressive disorder (MDD) in adolescents is reviewed and compared with that of depressed adults. Biological and psychosocial treatment approaches with adults and adolescents are then contrasted and the applicability of adult interventions to adolescents is examined. Some biological, cognitive, and experiential differences between adult and adolescent MDD may have treatment implications which have not yet been adequately addressed in the field. No effective treatments for adolescent MDD have, as yet, been developed or empirically tested. Based upon the results of this review, suggestions are made for the direction of future research.

Structured diagnostic interviews and clinicians' discharge diagnoses in hospitalized adolescents

OBJECTIVE

In this study Diagnostic Interview Schedule for Children (DISC-C) and clinicians' discharge diagnoses, as well as clinicians' admission and discharge diagnoses were compared.

METHOD

Patients (N = 163) ages 12 to 16 were interviewed with the DISC-C during the first month of admission. The frequencies for different diagnoses by DISC-C and by clinicians at the time of admission and discharge were tabulated. Kappa coefficients were obtained from cross-tabulated frequencies of DISC and clinicians' discharge diagnoses.

RESULTS

At discharge, the clinicians diagnosed more patients with multiple diagnoses and also diagnosed more patients with conduct and substance abuse disorders, dysthymia, and psychosis than they did at admission. The DISC-C diagnosed more patients with these disorders, except with psychosis, than did clinicians at either admission or discharge. The agreement between the clinicians' discharge and DISC-C diagnoses remained low across the diagnostic categories.

CONCLUSIONS

These findings support the view that the comprehensiveness and structure of the DISC-C can contribute to the sensitivity of the diagnostic process.

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.

Nocturnal cortisol, thyroid stimulating hormone, and growth hormone secretory profiles in depressed adolescents

Twelve depressed adolescents and 12 controls matched for age, sex, Tanner stage, time of menstrual cycle (females), weight, and time of year assessed were studied over 3 nights. Measurements for cortisol, thyroid stimulating hormone, and growth hormone were made on serum collected at 10 P.M., 12 midnight, 1 A.M., 2 A.M., 3 A.M., 4 A.M., and 6 A.M. in eight pairs and every 20 minutes from 8 P.M. to 7 A.M. in four pairs. Cortisol secretion did not significantly differentiate the groups. Thyroid stimulating hormone secretion was significantly elevated in the depressed group at one time point. Growth hormone secretion significantly differentiated the two groups at most time points, and the depressed adolescents significantly hypersecreted growth hormone (area under the curve). Implications for the diagnosis, etiology, and treatment of adolescent depression are discussed.

Comorbidity in the interpretation of dexamethasone suppression test results in children: a review and report

The dexamethasone suppression test (DST) was administered as part of the initial clinical assessment to 83 children and adolescents who were consecutively referred for outpatient evaluation. All diagnoses were made clinically by a child psychiatrist according to DSM-III criteria. A weight-corrected dose of dexamethasone of 17 micrograms/kg was used. DSM-III diagnoses were made independent of DST results. Patients were stratified into four main diagnostic groups: major depressive disorder (MDD) (N = 27); attention deficit disorder with hyperactivity (ADDH) (N = 22); major depressive disorder plus attention deficit disorder with hyperactivity (MDD + ADDH) (N = 29); and psychiatric controls (PC) (N = 5). Rates of dexamethasone nonsuppression were found to be similarly elevated in children with MDD (29.6%), ADDH (22.7%), and MDD + ADDH (37.9%). All 5 psychiatric control patients had a normal postdexamethasone suppression (0%). A similar pattern of results emerged in a reexamination of the literature on available studies of DST in juveniles which revealed that children with major affective disorders, attention deficit disorder (ADDH), and anxiety disorders had comparable DST results that were significantly higher than the 5.6% rate found in normal controls. These findings provide further support for similarities in DST results between ADDH and MDD in outpatients. Although these results suggest a lack of specificity of the DST as a laboratory aid for the diagnosis of juvenile affective disorders, they are also consistent with findings indicating that the DST may be an index of clinical severity and other findings suggesting a possible association between ADDH and MDD. Despite its limitations, the DST may provide potentially useful clinical and research information regarding the pathophysiology of psychiatric disorders and in alerting clinicians to the presence of serious psychiatric disorders. The findings also stress the relevance of assessing comorbidity in interpreting DST results.