Recent life events, cortisol, dehydroepiandrosterone and the onset of major depression in high-risk adolescents

Adolescent depression: description, causes, and interventions

Depression is one of the most prevalent of the psychiatric disorders and is common among individuals with epilepsy. Depression often begins in adolescence. The present review focuses on adolescent depression. In particular, this review first summarizes the definition, description, and classification of adolescent depression. Next, potential causes of adolescent depression are reviewed from a vulnerability-stress perspective. This part of the review focuses on the role of stressors and how stressors interact with genetic, biological, cognitive, personality, and interpersonal vulnerabilities to predict adolescent depression. Last, clinical aspects of adolescent depression are reviewed, including treatment and prevention of depression and the relation to epileptic disorders in adolescence. In sum, a substantial percentage of youth with epilepsy and seizures exhibit depression, and many are not diagnosed or treated in a timely manner. The present review shows that there are valid, empirically based assessments, treatments, and preventions for depression in adolescence that hold promise for reducing the significant burden associated with depression.

Adolescent depression: challenges and opportunities: a review and current recommendations for clinical practice

Many aspects of the treatment for adolescent depression are still uncertain. However, our body of knowledge continues to accumulate, and our approaches continue to be refined. When we remember that 40 years ago the field was still arguing about the existence of depression in youth, it is clear that significant progress has been made. Recent controversies have provided another opportunity to step back and re-evaluate. Given the chronicity, morbidity, and mortality associated with adolescent depression, the risks of doing nothing are too great. Evidence-based research has provided us with some direction during this unsettling time. After careful reviews, the major professional organizations representing pediatric medicine and psychiatry all support the continued use of SSRI antidepressant medications but emphasize close monitoring. The debates also have heightened interest in effective psychotherapy approaches, particularly CBT and IPT. Given the risk for suicidality in depressed adolescents, assessment and management of safety concerns remain critical, regardless of medication usage. Above all, it is most important that we remain hopeful about our ability to guide adolescents and families through the struggles with depression toward recovery.

General psychiatrists and their patients' children: assessment and prevention

General psychiatrists frequently treat adult patients with Major Depressive Disorder. Ordinarily, these psychiatrists focus solely on the treatment of their adult patients. However, new data suggest that treatment efforts might be doubly rewarded if psychiatrists tended to the children of these patients as well. This article reviews the literature on children whose parents have Major Depressive Disorder, and on preventive interventions for their children. We also review challenges to funding interventions of this sort based on systematic interviews of public and private insurance providers. We suggest a new standard of care for depressed patients: reliable screening of the patients' children for both risk of disorder and resilience as well as referral of these children, where indicated, for prevention services. We review obstacles to this standard of care: the professional reluctance of general psychiatrists to work with children and the lack of screening and preventive services for these children in most practice settings.

Attachment and adolescent depression: The impact of early attachment experiences

Bowlby's (1969/1982) ideas of attachment as an interactional system provide the basis for an understanding of the development of adaptive and maladaptive working models of the self and other. More specifically, attachment theory can offer an in-depth understanding into the development of a depressotypic self-schema. Attachment theory is set alongside research into adolescent depression in order to illustrate the importance of the primary attachment relationship in protecting adolescents in our society from developing depressive symptomatology. Therefore, current research in adolescent depression is viewed through the lens of attachment theory. This view is complemented by an exploration of the role of culture in the production of gender differences in depression. Thus, a tripartite model of adolescent depression, including the individual, family relationships, and socio-cultural factors is offered as being of potential value for clinicians and researchers in this area.

Prenatal anxiety predicts individual differences in cortisol in pre-adolescent children

BACKGROUND

Animal studies suggest that prenatal stress is associated with long-term disturbance in hypothalamic-pituitary-adrenal (HPA) axis function, but evidence in humans is lacking. This study examined the long-term association between prenatal anxiety and measures of diurnal cortisol at age 10 years.

METHODS

Measures of cortisol were collected at awakening, 30 min after awakening, and at 4 pm and 9 pm on 3 consecutive days in a sample of 10-year-olds (n = 74) from the Avon Longitudinal Study of Parents and Children, a prospective longitudinal cohort study of mothers and children on whom measures of anxiety and depression were collected in pregnancy and the postpartum period. Analyses examined the links between symptoms of prenatal anxiety and multiple indicators of cortisol, an index of HPA axis functioning.

RESULTS

Prenatal anxiety was significantly associated with individual differences in awakening and afternoon cortisol after accounting for obstetric and sociodemographic risk (partial correlations were .32 and .25, p < .05). The effect for awakening cortisol remained significant after controlling for multiple postnatal assessments of maternal anxiety and depression.

CONCLUSIONS

This study provides the first human evidence that prenatal anxiety might have lasting effects on HPA axis functioning in the child and that prenatal anxiety might constitute a mechanism for an increased vulnerability to psychopathology in children and adolescents.

O papel dos glicocorticóides na expressão dos sintomas de humor: uma revisão

O objetivo desta revisão é verificar, na literatura, uma relação entre níveis plasmáticos aumentados de corticosteróides e sintomas psiquiátricos, identificar as manifestações clínicas mais comuns e os tratamentos propostos. Alterações no eixo hipotálamo-hipófise-supra-renal levando a hipercortisolemia estariam associadas a distúrbios do humor, sobretudo depressão, enquanto que o uso de drogas glicocorticóides estaria relacionado ao aparecimento de sintomas psiquiátricos, como mania, depressão, labilidade afetiva e psicose. O levantamento bibliográfico foi realizado através dos indexadores Medline e Bireme no período de 1993 a 2003, em inglês, francês e espanhol, utilizando-se o cruzamento das seguintes palavras-chave: cortisol, corticosteróides, depressão, transtorno bipolar e psicose. Foram incluídos artigos originais (33) e de revisão (22) e excluídos relatos de caso. Alguns estudos sugerem que altas concentrações plasmáticas de cortisol, em longo prazo, podem levar à depressão, propondo que a utilização de drogas antiglicocorticóides teria efeito antidepressivo. Outros estudos, por outro lado, indicam não haver associação entre hipercortisolemia e episódios depressivos.

Pubertal neuromaturation, stress sensitivity, and psychopathology

Normal adolescent development is often accompanied by transient emotional and behavioral problems. For most individuals with postpubertal-onset adjustment problems, there is a resolution by early adulthood and relative stability through the adult life span. But for a minority, adjustment problems escalate during adolescence and portend the development of serious mental illness in adulthood. In this article, we explore adolescent behavioral changes and neurodevelopmental processes that might contribute to stress sensitivity and vulnerability for the emergence of the mental disorders. Of particular interest is the role that hormonal changes might play in the expression of genetic vulnerabilities for psychopathology. Drawing on recent findings from clinical research and behavioral neuroscience, we describe the ways in which postpubertal hormones might alter brain function and, thereby, behavior. It is concluded that there are both activational and organization effects of hormones on the adolescent brain, and these contribute to developmental discontinuities in behavioral adjustment. Implications for adult psychopathology and preventive intervention are discussed.

Low salivary cortisol levels and externalizing behavior problems in youth

Research linking basal cortisol levels with internalizing and externalizing behavior problems in youths has yielded inconsistent results. We hypothesize that the high moment to moment variation in adrenocortical activity requires an analytical strategy that separates variance in cortisol levels attributable to "stable traitlike" versus "state or situationally specific" sources. Early morning saliva samples were obtained from 724 youths (M age = 13.5 years; range = 6-16 years in Year 1) on 2 successive days 1 year apart. Latent state-trait modeling revealed that 70% of the variance in cortisol levels could be attributed to statelike sources, and 28% to traitlike sources. For boys only, higher levels of externalizing problem behaviors were consistently associated with lower cortisol attributable to traitlike sources across 3 years of behavioral assessment. The inverse association between individual differences in cortisol and externalizing problem behavior has previously only been reported in studies of at-risk or clinical groups. The present findings suggest the relationship is a stable phenomenon that spans both normative and atypical child development. Studies are needed to reveal the biosocial mechanisms involved in the establishment and maintenance of this phenomenon, and to decipher whether individual differences in this hormone-behavior link confers risk or resilience.

Stress and Depression

Improved methods of assessment and research design have established a robust and causal association between stressful life events and major depressive episodes. The chapter reviews these developments briefly and attempts to identify gaps in the field and new directions in recent research. There are notable shortcomings in several important topics: measurement and evaluation of chronic stress and depression; exploration of potentially different processes of stress and depression associated with first-onset versus recurrent episodes; possible gender differences in exposure and reactivity to stressors; testing kindling/sensitization processes; longitudinal tests of diathesis-stress models; and understanding biological stress processes associated with naturally occurring stress and depressive outcomes. There is growing interest in moving away from unidirectional models of the stress-depression association, toward recognition of the effects of contexts and personal characteristics on the occurrence of stressors, and on the likelihood of progressive and dynamic relationships between stress and depression over time-including effects of childhood and lifetime stress exposure on later reactivity to stress.

Moods in everyday situations: effects of menstrual cycle, work, and stress hormones

OBJECTIVE

This study examined women's mood responsiveness on work and off days during different phases of the menstrual cycle.

METHODS

Self-reports of negative, positive, and energy dimensions of mood were obtained throughout the day on two work and two off days during the luteal and follicular phases of the menstrual cycle in 203 women nurses. Individual differences in daytime and nighttime epinephrine, norepinephrine, and cortisol were assessed.

RESULTS

High daytime norepinephrine, epinephrine, and cortisol levels were associated with higher ratings of stress and tired, and with lower ratings of happy. The phase of the menstrual cycle and the day factor (workday, off day) were also associated with mood differences, and the direction of the effects depended on hormone levels and hormone sampling period.

CONCLUSION

The experience of moods is affected by the arousal-related interaction of hormone levels with the phase of the menstrual cycle and occupational stress.

Changes in financial strain over three years, ambulatory blood pressure, and cortisol responses to awakening

OBJECTIVE

Chronic psychosocial stress has been associated cross-sectionally with ambulatory blood pressure and with salivary cortisol, but there have been few longitudinal studies of the effects of changes in chronic stress. We assessed the influence of changes in financial strain on ambulatory blood pressure and salivary cortisol.

METHODS

Data were analyzed from 160 men and women age 47 to 59 years at the first assessment (T1) who repeated ambulatory monitoring 3 years later (T2). We analyzed change in financial strain as a continuous variable, and specifically compared people who did and did not report an improvement in financial strain.

RESULTS

Change in financial strain was associated with change in ambulatory systolic pressure after controlling for T1 ambulatory systolic pressure, gender, socioeconomic position, age, smoking, body mass index, and T1 financial strain (p = .041). Systolic pressure at T2 was lower in the improved financial strain (121.7 +/- 11.2 mm Hg) than in the worse/no change group (125.5 +/- 11.5 mm Hg; p = .029). The corresponding diastolic pressures averaged 78.5 +/- 7.1 mm Hg and 80.7 +/- 7.9 mm Hg, respectively (p = .061). The cortisol awakening response (difference between waking and 30 minutes later) was lower (p = .048) in men who reported improved financial strain, controlling for T1 cortisol response, socioeconomic position, age, smoking, time of waking, and T1 financial strain. There were no differences in the slope of cortisol decline over the day or in evening values.

CONCLUSION

These longitudinal data extend cross-sectional findings in showing associations between favorable changes in chronic stress and reduced cardiovascular and neuroendocrine activation in everyday life.

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.

Serotonin modulates the suppressive effects of corticosterone on proliferating progenitor cells in the dentate gyrus of the hippocampus in the adult rat

This series of experiments explores the interaction between corticosterone and serotonin (5-HT) in the regulation of cell proliferation in the dentate gyrus of the adult rat. Intracerebroventricular 5,7-DHT (5,7-dihydroxytryptamine) (either 200 or 300 microg) resulted in highly significant depletion of 5-HT as measured by high performance liquid chromatography in the frontal cortex but had no effect on the number of proliferating cells in the dentate gyrus by measuring 5-bromo-2'-deoxyuridine (BrdU) and Ki-67 cytochemistry. Treatment with PCPA (p-chlorophenylalanine: a tryptophan hydroxylase inhibitor: 300 mg/kg initially followed by 100 mg/kg/day) resulted in reduced proliferation as measured by Ki-67 after 3 days treatment, but not by BrdU uptake, and not after 14 days treatment by either method. In addition, injection of corticosterone (10-40 mg/kg/day) for 8 days significantly reduced proliferation in the dentate gyrus, as expected, measured by both BrdU uptake and Ki-67 immunostaining. Adrenalectomized (ADX) rats with a replacement subcutaneous pellet of corticosterone showed reduced proliferation when given additional corticosterone (10 mg/kg/day for 8 days), but this was prevented by 5-HT depletion (i.c.v. 5,7-DHT). Finally, a dose-response study showed that progressive doses of corticosterone (0-40 mg/kg/day) in ADX rats resulted in diminished suppression of proliferation in 5-HT-depleted compared with 5-HT-intact rats. These results strongly suggest that 5-HT regulates the sensitivity of proliferating cells in the dentate gyrus to corticosterone.

Cognition in mania and depression: psychological models and clinical implications

Affective disorders, including bipolar disorder and major depressive disorder, are highly prevalent throughout the world and are extremely disabling. Diagnostic and Statistical Manual criteria and psychological models strongly implicate cognitive dysfunctions as being integral to our understanding of these disorders. We review the findings from studies that have used neurocognitive tests and functional imaging techniques to explore abnormal cognition in affective disorders. In particular, we highlight the evidence for cognitive dysfunctions that persist into full clinical remission, and the recent trend toward the use of "hot" processing tasks, involving emotionally charged stimuli, as a means of differentiating between the cognitive underpinnings of mania and depression. The clinical relevance of these developments is discussed.

The effects of child maltreatment on the hypothalamic-pituitary-adrenal axis

Abnormal functioning of the hypothalamic-pituitary-adrenal (HPA) axis, a critical mammalian stress response system, has been associated with emotional responses such as anxiety and depression, as well as with behavioral and cognitive processes such as aggression, learning and memory deficits, and failure of response inhibition. This review examines the evidence for HPA axis dysregulation related to childhood maltreatment. It is concluded that child maltreatment may lead to disruptions in HPA axis functioning, and that factors such as age of maltreatment, parental responsiveness, subsequent exposure to stressors, type of maltreatment, and type of psychopathology or behavioral disturbance displayed may influence the degree and patterning of HPA disturbance.

A prospective test of the stress-buffering model of depression in adolescent girls: no support once again

The stress-buffering model posits that social support mitigates the relation between negative life events and onset of depression, but prospective studies have provided little support for this assertion. The authors sought to provide a more sensitive test of this model by addressing certain methodological and statistical limitations of past studies with prospective data from 496 adolescent girls. Deficits in peer support predicted increases in depressive symptoms, and negative life events predicted onset of depressive pathology. However, none of the 14 prospective tests provided support for the stress-buffering model despite sufficient power. Results provide scant support for the stress-buffering model and suggest that it might be time to shift attention to alternative multivariate models concerning these risk factors.

Sex differences in the effects of pubertal development on responses to a corticotropin-releasing hormone challenge: the Pittsburgh psychobiologic studies

We propose that sex differences in HPA regulation may emerge during puberty and help to explain sex differences in depression. In this study, we examined sex differences in cortisol responses to CRH challenge across pubertal stages in carefully screened control subjects from the Pittsburgh Psychobiologic Studies. Participants were 7-16 years of age, physically healthy, and had no personal or family history of psychiatric disorder. Physician-rated Tanner staging was conducted, followed by CRH challenge sessions including 30-40 minutes pre-infusion baseline, 1 microg/kg CRH infusion, 90-180 minutes of post-infusion measures, and 9-10 plasma cortisol samples. Girls showed increasing total cortisol responses to CRH across Tanner stages, explained by slower recovery from peak cortisol levels, while boys showed similar total responses across Tanner stages. Results show subtle sex differences in the influence of puberty on HPA regulation at the pituitary level, which may represent one factor underlying the emergence of girls' greater rates of depression during this time.

Trier Social Stress Test

BACKGROUND

Researchers face the difficulty of inducing psychosocial stress in a laboratory setting using a method that institutional review boards could consider an acceptable research protocol.

METHODS

This article describes the Trier Social Stress Test, a research protocol that can be used to induce psychosocial stress and capture the integrated aspects of an individual's biologic and psychological responses.

RESULTS

The test involves 15 minutes of psychosocial stress induced by a mock job interview and followed by a mental arithmetic challenge before a panel of three judges. The discomfort associated with performance requirements induces stress in socially acceptable ways that can be measured using physiologic and/or psychological parameters.

CONCLUSIONS

This method allows stress to be induced and measured in a controlled, laboratory setting.

Life events, social support, and onset of major depressive episode in Finnish patients

We investigated differences in life events and social support between subgroups of depressed patients and the distribution of life events in phases preceding or during depression. In the Vantaa Depression Study, 269 psychiatric patients with DSM-IV major depressive disorder were diagnosed with Schedule for Clinical Assessment in Neuropsychiatry, Version 2.0, and Structured Clinical Interview for DSM-III-R personality disorders (SCID-II). Life events during the 12 months preceding the interview were investigated with the Interview for Recent Life Events, and social support with the Interview Measure of Social Relationships and the Perceived Social Support Scale-Revised. Nearly all patients (91%) reported life events, on average 4.1 per preceding year. No major differences between sociodemographic or clinical subgroups were found; the frequency of events was somewhat greater among the younger subjects, whereas those with comorbid alcoholism or personality disorders perceived less social support. Although events were distributed evenly between the time preceding depression, the prodromal phase, and the index major depressive episode, two thirds of the patients attributed their depression to some event. Despite clinical and sociodemographic heterogeneity, patients with major depressive disorder are fairly homogeneous in terms of life events during the preceding year. Events do not cluster in any particular phase of the progression to an episode.

Effects of trauma exposure on the cortisol response to dexamethasone administration in PTSD and major depressive disorder

OBJECTIVE

To evaluate cortisol suppression following 0.5 mg of dexamethasone (DEX) in trauma survivors (N=52) with posttraumatic stress disorder (PTSD), major depressive disorder (MDD), both, or neither disorder, and in subjects never exposed to trauma (N=10), in order to examine interactions between diagnosis and trauma history on cortisol negative feedback inhibition.

METHOD

Lifetime trauma exposure and psychiatric diagnoses were assessed and blood samples were obtained at 8:00 a.m. for the determination of baseline cortisol. Participants ingested 0.5 mg of DEX at 11:00 p.m. and blood samples for determination of cortisol and DEX were obtained at 8:00 a.m. the following day.

RESULTS

PTSD was associated with enhanced cortisol suppression in response to DEX. Among trauma survivors, the presence of a traumatic event prior to the "focal" trauma had a substantial impact on cortisol suppression in subjects with MDD. Such subjects were more likely to show cortisol alterations similar to those associated with PTSD, whereas subjects with MDD with no prior trauma were more likely to show alterations in the opposite direction, i.e. relative non-suppression.

CONCLUSIONS

Cortisol hypersuppression in PTSD appears not to be dependent on the presence of traumatic events prior to the focal trauma. However, prior trauma exposure may affect cortisol suppression in MDD. This finding may have implications for understanding why only some depressed patients show non-suppression on the DST.

Exposure to postnatal depression predicts elevated cortisol in adolescent offspring

BACKGROUND

Animal research shows that early adverse experience results in altered glucocorticoid levels in adulthood, either raised basal levels or accentuated responses to stress. If a similar phenomenon operates in humans, this suggests a biological mechanism whereby early adversity might transmit risk for major depression, glucocorticoid elevations being associated with the development of this disorder.

METHODS

We measured salivary cortisol at 8:00 am and 8:00 pm over 10 days in 13-year-old adolescents who had (n = 48) or had not (n = 39) been exposed to postnatal maternal depression.

RESULTS

Maternal postnatal depression was associated with higher, more variable morning cortisol in offspring, a pattern previously found to predict major depression.

CONCLUSIONS

Early adverse experiences might alter later steroid levels in humans. Because maternal depression confers added risk for depression to children, these alterations might provide a link between early events and later psychopathology.

High levels of cortisol among adolescent offspring of parents with bipolar disorder: a pilot study

The hypothalamic-pituitary-adrenal (HPA) axis is compromised at several levels in major depressive and bipolar disorder (BD). However, it is not known whether HPA abnormalities predate the onset of these disorders. We conducted a pilot study comparing salivary cortisol levels of 10 adolescent offspring of parents with BD and 10 offspring of parents with no mental disorder (NMD). For two days, samples were collected at awakening and during the day in the adolescents' natural environment. The offspring of parents with BD had higher mean cortisol levels in the mornings and afternoons than the offspring of parents with NMD. When controlling for age, group differences in cortisol persisted in the afternoon, but not morning samples. None of the adolescents met diagnostic criteria for anxiety, affective, attention-deficit, or conduct disorders. Although preliminary, the results suggest that there is an early abnormality in the HPA system of the offspring of parents with BD.

The stressful life events schedule for children and adolescents: development and validation

The development and psychometric properties of the Stressful Life Events Schedule (SLES), an interview instrument to assess stressors in children and adolescents, are described. Children (< or =12 years) and adolescents (>12 years) with psychopathology (n=30) and non-psychiatric controls (n=30) were interviewed with the SLES about the occurrence of stressful life events during the prior year. To examine concurrent validity of the SLES, all subjects also completed the self-report Life Events Checklist (LEC) and half the sample completed the Life Events and Difficulties Schedule (LEDS). To examine informant validity, the parent/guardian also reported on stressful life events occurring to their child during the year prior to interview. Test-retest reliability of the SLES was examined by re-assessing all children approximately one week after the initial interview. Subjects rated subjectively how stressful an event was on a 4-point scale. Additionally, panel ratings of objective stress and behavior-dependence/independence were made on 4-point scales. The SLES was found to have substantial inter-rater consensus reliability for objective threat (kappa=0.67) and almost perfect reliability for event behavior-dependence/independence (kappa=0.84). Similarly, the test-retest reliability of the SLES was also found to be substantial at the level of specific event comparisons (kappa=0.68). The SLES discriminated between children with and without psychopathology on all measures of stressful life events. Total stressful life events assessed with the SLES concurred well with those assessed by the LEC (ICC=0.83) and the LEDS (kappa=0.77) although, as expected, examination of specific events showed much smaller overlap between the SLES and the LEC (kappa=0.26). Child-parent agreement for the occurrence of severe events was substantial (kappa=0.73) but tended to be only moderate when all events were examined (kappa=0.48). The results of this study indicate that the SLES has good psychometric properties. The SLES is a useful, cost-effective tool for assessing stressful life events in children and adolescents.

Early experience and depressive disorders: human and non-human primate studies

This paper reviews evidence from both human and non-human primate studies concerning the role of early adverse experiences in the onset and course of adult depressive disorders. Despite accumulating evidence that stressful life events can play a major role in precipitating the onset of depressive episodes in humans, the mechanisms by which early experiences mediate and moderate the risk for later affective illnesses are not fully understood. Experimental paradigms in primates have documented the important role of undeveloped (social deprivation) or disrupted attachment systems (social separation). Effects of early social deprivation can be seen in many domains. Behavioral effects include repetitive idiosyncratic behaviors, increased self-directed behaviors, inappropriate expression of aggressive behaviors, non-modulated patterns of consumption, and inappropriate sexual and maternal behaviors. Cognitively, such animals require longer habituation time for any task and demonstrate increased perseverance on tasks following non-reward. Physiological effects include an altered hypothalamic-pituitary-adrenal response to stress, changes in diurnal temperature regulation, and alterations in immune function. Neurochemical effects include abnormalities in noradrenergic, serotonergic, and dopaminergic systems. Even neuroanatomical changes following early social deprivation have been reported. Studies with primates have also confirmed that early maternal and peer separations are major behavioral and neurobiological events with both short- and long-term consequences that parallel human depression. Future utilization of experimental paradigms in non-human primates may assist in better understanding the role of early experiences in predisposing to the development of affective illnesses in humans. This review concludes by presenting a model for understanding a developmentally based vulnerability to adult depressions.

Effects of low-frequency cranial electrostimulation on the rest-activity rhythm and salivary cortisol in Alzheimer's disease

OBJECTIVE

In previous studies, cranial electrostimulation (CES) had positive effects on sleep in depressed patients and in patients with vascular dementia. The present study examined the effects of low-frequency CES on the rest-activity rhythm and cortisol levels of patients with probable Alzheimer's disease (AD).

METHOD

It was hypothesised that a decreased level of cortisol would parallel a positive effect of low-frequency CES on nocturnal restlessness. Sixteen AD patients were randomly assigned to an experimental group (n = 8) or a control group (n = 8). The experimental group was treated with CES, whereas the control group received sham stimulation, for 30 minutes a day, during 6 weeks. The rest-activity rhythm was assessed by actigraphy. Cortisol was measured repeatedly in the saliva throughout the day by means of salivette tubes.

RESULTS

Low-frequency CES did not improve the rest-activity rhythm in AD patients. Moreover, both groups showed an increase instead of a decrease in the level of cortisol.

CONCLUSIONS

These preliminary results suggest that low-frequency CES has no positive effect on the rest-activity rhythm in AD patients. An alternative research design with high-frequency CES in AD is discussed.

Predictors of response to treatment in children and adolescents with mood disorders

Depression and bipolar disorder are frequently chronic disorders, with onset often beginning in childhood. Mood disorders are becoming more recognized in children and adolescents, and treatment of these disorders has received much attention, particularly in the past 10 years. Recent studies have demonstrated efficacy of antidepressant medications (particularly SSRIs) and specific psychotherapies (primarily CBT). Rates of remission (little or no symptoms) in these studies, however, have remained quite low (35% to 40% in most acute studies). Furthermore, recurrence is common in this population, and affects 40% to 50%. Early onset mood disorders are also associated with increased risk of developing other psychiatric disorders, substance abuse, and suicide, and having poor academic, work, and social functioning. The lifelong implications are serious. Identifying factors that may predict response to treatment, both in general and to specific treatments, may lead to improved outcomes for these patients. Unfortunately, studies have typically been inconsistent. Most studies do not identify demographic variables as predictive of outcome, although older age has been associated with poor prognosis in several studies. Psychosocial factors have yielded some results, particularly with regard to family environments. Generally, intact families with positive interaction styles and less dysfunction have been associated with better outcomes. Psychiatric disorders among parents not only predicts the development of the disorder, but is also associated with poorer prognosis. Finally, several clinical factors have been linked to poorer outcome in children and adolescents with mood disorders. More frequent episodes, increased severity (particularly suicidality and psychosis), and comorbid disorders are likely to lead to fewer recoveries, longer episodes, and increased rate of recurrence. Recent attention has focused on mediators and moderators of outcomes to treatment. In general, the theory is that enumerable factors contribute to the course of an individual's mood disorder, but that by identifying some of the variables that have more impact may allow for more specific or modified treatments to improve outcome. Many of the predictive factors explored in this article are examples of mediators and moderators that affect outcome. Each one alone may not provide definitive answers for predicting response to treatment, but each must be taken into account at the outset of treatment. It is clear that treatments must be individualized for each patient. Furthermore, selecting only one treatment exclusively for patients may hinder progress. The first step is to attempt to identify some of the underlying causes and the consequences of the disorder itself (i.e., decreased social interaction). The next step in successful treatment is to address both the causes and consequences of the disorder, through medication, psychotherapy, skills training, family intervention, or any other methods needed to assist the child to begin functioning better in all domains (social, academic, work, family, and so forth). Such a biopsychosocial approach to treatment of these disorders will likely improve overall outcome.

Heritability of cortisol levels: review and simultaneous analysis of twin studies

Cortisol has a pivotal role in physical and mental health, but relatively few studies have paid attention to individual differences in cortisol levels and the etiology of these differences, in particular their possible genetic basis. In this article we review the existing literature on the heritability of cortisol levels. Most of the studies, which have been carried out in genetically informative samples, lack methodological consistency with regard to frequency and timing of sample collection. The circadian rhythm in cortisol levels was often not taken into account. A power analysis shows that none of these studies used adequate sample sizes to distinguish genetic from shared environmental influences as a cause for familial aggregation. Results of a simultaneous analysis of 5 comparable twin studies suggest a heritability of 62%. Hence, we conclude that, to understand the contribution of genetic and (shared) environmental influences to variation in basal cortisol levels, future studies should be designed more rigorously with strict collection and sampling protocols, sufficient sample size and repeated measures across multiple days.

The roots of depression in adolescent girls: is menarche the key?

Before adolescence, the rates of depression are similar in girls and boys (or are slightly higher in boys). Yet with the onset of puberty, the gender proportion of depression dramatically shifts to a two girls to one boy ratio. What, then, is the relationship between menarche and the onset of major depression in early adolescence? Recent literature intimates that vulnerability to depression may be rooted in an intricate meld of genetic traits, normal female hormonal maturational processes, and gender socialization. Information regarding gender differences in the presentation of depressive symptoms is provided along with biologic, psychologic, and sociologic factors contributing to depression in adolescent girls. The burden of illness associated with onset of depression after menarche reinforces the importance of prevention or else expeditious recognition and intervention.

Bio-social origins of depression in the community. Interactions between social adversity, cortisol and serotonin neurotransmission

BACKGROUND

Social adversity may be a risk factor for depression, by increasing cortisol secretion, which impairs serotonin (5-HT) neurotransmission.

AIMS

To examine this causal pathway in a community setting.

METHOD

Women who were currently ICD-10 depressed (n=94), vulnerable to depression but not depressed (n=166) and non-vulnerable controls (n=177) were recruited. We assessed social adversity and vulnerability (Life Events and Difficulties Schedule; Self Evaluation and Social Support Scales) and psychiatric state (Schedules for Clinical Assessment in Neuropsychiatry). Salivary cortisol concentrations were measured at 09.00 and 23.00 h. Serotonin function was assessed using prolactin responses to dexfenfluramine.

RESULTS

Cortisol concentrations were not increased in the depressed or vulnerable. Morning salivary and serum cortisol were reduced in depression. Evening cortisol was increased after recent life events. Life events and depression were associated with increased prolactin responses.

CONCLUSIONS

The hypothalamic-pituitary-adrenal axis is sensitive to social stress but does not mediate vulnerability to depression. Exaggerated 5-HT(2) receptor responsiveness to stress may play a role in the evolution of depression.

Psychosocial and endocrine features of chronic first-episode major depression in 8-16 year olds

BACKGROUND

Psychoendocrine processes may have a role in explaining individual differences in the outcome of major depression in 8-16-year-old school children.

METHODS

Salivary cortisol and dehydroepiandrosterone (DHEA) levels at 8:00 AM and 8:00 PM, life events, and comorbidity were assessed at presentation, 36, and 72 weeks in 47 (60%) of 78 clinically referred subjects with a first episode of major depression. Comparisons were made between chronic and nonchronic major depression.

RESULTS

Chronic depression was characterized by being older, cortisol hypersecretion at 8:00 PM at all three assessments, increasing depression-dependent life events over the follow-up period, and comorbid obsessive-compulsive disorder (OCD) at presentation and at 36 weeks. Chronicity may be best predicted by increasing depression-dependent events over the 72-week period. Such events are more likely in cases with evening cortisol hypersecretion at entry and persistent OCD. Variations in DHEA levels were not associated with chronicity or increasing life events.

CONCLUSIONS

During adolescence, but not childhood, the persistence of major depression may occur through an increase of risk for further and particular types of depression-dependent undesirable life events (personal disappointments and/or dangers to the self), that are more likely in those subjects with persisting cortisol hypersecretion and unresolved comorbid OCD.

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.

Recent developments in understanding the psychosocial aspects of depression

Recent advances in the psychosocial understanding of depression have elaborated an already complex aetiological model. Yet each new strand seems to echo, and forge links with, themes uncovered earlier, making it easier to see what is common about the 'final common pathway' to onset. For example, although recent stressors have for some time been recognised predictors of onset, new insights about the origins of these stressors have overlapped with other new work on depression and childhood adversity to identify a group who 'produce' their own severe life events in response to early negative experience. And recent studies have traced the well-known gender difference in depressive prevalence to differences both in gender role involvement with the provoking life events and in styles of support-seeking/ support-giving. What emerges is the powerlessness, loss and humiliation characterising the final pathway. Both naturalistic studies and controlled trials suggest that psychosocial situations reflecting the opposite emotional meaning, that is new hope, characterise a similar pathway to remission. Conclusions speculate whether awareness of this pathway might enhance purely pharmacological treatment.

Morning cortisol as a risk factor for subsequent major depressive disorder in adult women

BACKGROUND

Whether individual differences in cortisol contribute to subsequent major depressive disorder (MDD) is unknown.

AIMS

To determine whether premorbid levels of salivary cortisol and dehydroepiandrosterone (DHEA) were associated with subsequent MDD and how these related to psychosocial factors known to increase the risk for MDD.

METHOD

Adult women (n=116) were recruited from general practices. None was currently depressed; 83 were 'psychosocially vulnerable' to MDD, 33 were not. Salivary steroids (cortisol and DHEA at 08.00 h and 20.00 h), recent life events, current mood and social support were assessed at entry. Onset of MDD was recorded during 13 months' follow-up.

RESULTS

There were no associations between salivary cortisol or DHEA and recent life events or vulnerability. Twenty-eight onsets of MDD occurred during the follow-up period. This was associated with: severe adverse life events and difficulties during the follow-up period; mean morning cortisol levels at entry; and the presence of any of three vulnerability factors.

CONCLUSIONS

Individual differences in morning salivary cortisol levels may represent an independent risk factor for subsequent MDD. The origin of these differences in cortisol is not yet understood.