Stress and the Brain

The Science of Mental Health

Steven E. Hyman

• Publisher: Routledge
• Year: 2013
• eBook ISBN: 9781317970965
• Topic: Psychology
• Subtopic: Mental Health in Psychology
• Index: Psychology

First published in 2002. This is Volume 9 of a collection of ten works on the science of mental health. This volume in the series focuses on issues related to stress and the brain. Although stress affects many other aspects of physiology, they are beyond the scope of this volume. The volume begins with a seminal work by Selye describing the stress response, an adaptive response that permits an organism not only to survive but also to cope with the stressor.

Can poverty get under your skin? Basal cortisol levels and cognitive function in children from low and high socioeconomic status

S. J. LUPIEN,^a,b S. KING,^a M. J. MEANEY,^a AND B. S. McEWEN^c
aDouglas Hospital/McGill University; ^bMontreal Geriatric Institute; and ^cRockefeller University
This study was supported by a grant from the John D. and Catherine T. MacArthur Foundation. S.J.L.'s work was supported by a scientist award from the Fonds de la recherche en santé du Quebec (FRSQ) and by a Young Investigator Award from the National Alliance for Research on Schizophrenia and Depression (NARSAD).
Address correspondence and reprint requests to: Sonia Lupien, PhD, Director, Laboratory of Human Psychoneuroendocrine Research, Douglas Hospital/McGill University, 6875 Boulevard Lasalle, Montreal PQ H4H IR3 Canada; E-mail: [email protected].

Abstract

It is well known that individuals from more advantaged social classes enjoy better mental and physical health than do individuals within lower classes. Various mechanisms have been evoked to explain the association between socioeconomic status (SES) and health. One mechanism that has received particular attention in recent years is stress. It has been shown that individuals lower in SES report greater exposure to stressful life events and a greater impact of these events on their life than individuals higher in SES. In order to measure whether the development of the relationship between SES and mental health is sustained by exposure to high levels of glucocorticoids, we measured morning salivary cortisol levels as well as cognitive function (memory, attention, and language) in 307 children (from 6 to 16 years of age) from low versus high SES in the Montreal area in Canada. The results revealed that low SES children from 6 to 10 years old present significantly higher salivary cortisol levels when compared to children from high SES. This difference disappears at the time of school transition, and no SES differences are observed in salivary cortisol levels during high school. However, children from low and high SES do not differ with regard to memory or to attentional and linguistic functions. Also, mothers of low SES children reported higher feelings of depression and more unhealthy behaviors, while mothers of high SES children reported higher stress related to work or family transitions. Altogether, these results show that low SES in young children is related to increased cortisol secretion, although the impact of SES on cortisol secretion is absent after transition to high school. These data are interpreted within the context of the equalization process of class patterning. Four social explanatory factors are suggested to explain the disappearance of SES differences in basal cortisol levels after school transition, taking into account the influence of family environment on the child's secretion of stress hormones.

It is well known that individuals from more advantaged backgrounds enjoy better health than do individuals from disadvantaged environments (Anderson & Armstead, 1995; Antonovsky, 1967). In the health literature, the terms "social class" and "socioeconomic status (SES)" are often used interchangeably. However, in disciplines such as sociology, they bear different meanings. "Social class" is a term widely used in theories of social ordering and class categories, such as Marx's theory (Wright & Perrone, 1977) and others. "SES," as used in the sociological literature, is function of education, income, or occupation (Dutton & Levine, 1989). Epidemiologic studies and census data have provided the most well known associations between SES and health. It has been shown that the risk of mortality, the prevalence and course of disease (Pincus, Callahan, & Burkhauser, 1987), and blood pressure (Dyer, Stamler, & Shekelle, 1976) increase significantly as employment grade (Marmot, Shipley, & Rose, 1984), occupational status (Adelstein, 1980), income (Pappas, Queen, Hadden, & Fisher, 1993), and years of education (Adelstein, 1980) decrease. A link has also been observed between SES and the prevalence and course of disease (Pincus et al., 1987). Finally, it has been shown that blood pressure is higher in individuals lower on the SES hierarchy (Dyer et al., 1976; Keil, Tyroler, & Sanfider, 1977; Matthews, Kelsey, & Meilahn, 1989; Syme, Oakes, & Friedman, 1974) and that this association is closely related to race, which in itself is closely associated with SES (Bureau of Labor Statistics, 1967; Kahn, Williamson, & Stevens, 1991; Keil et al., 1977; Susser, Watson, & Hopper, 1985). Although most of the literature on the association between SES and health has concentrated on systemic disease, other studies have shown a significant relationship between SES and mental health. Inverse associations have been reported between SES and prevalence of schizophrenia (Dohrenwend, 1990), as well as between SES and depression (Hirschfeld & Cross, 1982).

The relationship between SES and health begins at the earliest stages of life (Anderson & Armstead, 1995). According to Star field (1982), who reviewed the literature on SES and child health, a SES-health linkage has been found with the following health problems: lead poisoning, vision problems, otitis media and hearing loss, cytomegalic inclusion disease, and iron deficiency anemia. Langford, Watson, and Douglas (1968) have reported results on 1,765 high school girls and showed that the lower the SES of the parents, the higher the blood pressure of the girls. In addition, mental retardation, learning disorders, and emotional and behavioral problems occur at greater frequency among children of lower SES (Anderson & Armstead, 1995). Another study by Ardila and Rosselli (1995) in Columbia reported significant developmental differences between children from high versus low SES: children from low SES showed deficits in language, memory, and attentional capacities when compared with children from high SES.

Mechanisms Underlying the Association Between SES and Health

Various mechanisms have been evoked to explain the association between SES and health. Three of them have received particular attention in recent years (for a review, see Adler, Boyce, Chesney, Folkman, & Syme, 1993; Boyce, Chesney, Cohen, Folkman, Kahn, & Syme, 1994). First, it has been proposed that the empirical link between SES and health is due to underlying genetic factors. Genetically based physical or mental factors might lead to lower social position and poorer health. As noted by many researchers (see Adler et al., 1994; Anderson & Armstead, 1995), this explanation is plausible but improbable because the association between SES and health persists even after adjusting for factors such as height, body mass index, and cognitive flexibility. Second, it is suggested that the association between SES and health is due to the influence of illness on SES, rather than of SES on illness. It has been reported that, although there is evidence that mental and physical disturbances may lead to lower SES, available data on this association does not explain it in its totality (see Anderson & Armstead, 1995). The third explanation for the association between SES and health is that SES may lead to behaviors that, in turn, will influence health status. Income, education, and occupation, which are all components of SES, may shape an individual's life course and determine his or her health outcome. The physical environment in which one lives, the social environment and associated vulnerability to interpersonal aggression and violence, and the health behaviors related to a particular lifestyle, as well as socialization and experiences, may all be candidate variables that may contribute to the association between SES and health (see McLeod & Kessler, 1990). For example, cigarette smoking (Winkleby, Fortmann, & Barrett, 1990) and lack of physical activity (Cauley, Donfield, Laporte, & Warhaftig, 1991) are inversely related to SES and are positively associated with poor health outcomes (Winkleby et al., 1990). Moreover, psychological characteristics such as anger and hostility, emotional suppression, depression, and pessimism or fatalism (for a review, see Scheier & Bridges, 1995) relate to both SES and disease risk (Barefoot, Dodge, & Peterson, 1989; Murphy, Olivier, Monson, & Sobol, 1991).

Although behavioral or personality traits may shed some light on the association between SES and health, they do not explain the significant relationships observed between SES and health in children (Langford et al., 1968), in whom such risk behaviors or personality traits may not yet be developed. Most of the research performed on the association between SES and health suggest that we should see the largest socioeconomic differences in health during middle and early old age because these age groups are most likely to be characterized by sizable socioeconomic differentials in exposure to risk factors (see House, Kepkowski, Kinney, Mero, Kessler, & Herzog, 1994; West, 1997).

Stress as the Missing Link?

So, health behaviors and personality traits represent two pathways by which SES may influence health, but they do not account for all of the association. Other potential pathways by which SES may influence health are through differential exposure of the individuals to physical and social contexts that may be damaging for their health. A factor that has received a great deal of attention in recent years is stress (for recent reviews, see Marmot & Feeney, 2000; Steptoe, 2000). Stress is generally defined as previous or actual exposure to life events that require adaptation from the individual (Selye, 1950), or else as a state occurring when an individual perceives that the demands of the environment exceeds his or her ability to cope (see Adler et al., 1994). The association between SES and health may result in part from differential exposure to stress. It has been shown that individuals from lower SES report greater exposure to stressful life events and a greater impact of these events on their life than individuals from higher SES (Dohrenwend, 1973). This suggests that individuals from lower SES may have greater vulnerability to stress and, subsequently, to disease.

The association between SES and stress may stem from environmental and social-psychological factors. With regard to environmental factors, it is known that, as one moves down the SES ladder, residential choices become more limited and many of the environments in which individuals lower on the SES hierarchy live are associated with increased mortality rate and crime (Haan, Kaplan, & Syme, 1989). It has been suggested that these differences in environments vary objectively in chronic exposures to stressor events (Harburg, Erfurt, Chape, Hauenstein, Schull, & Schork, 1973). With regard to sociological-psychological factors, it has been shown that higher SES decreases the likelihood of exposure to negative events such as social aggression and risk behaviors (Dohrenwend & Doh renwend, 1970). Individuals of lower SES are exposed to a higher rate of change or instability in their lives, and this instability has been found to produce a higher level of individual distress in lower SES individuals (Broadhead, Kaplan, & James, 1983; Dohrenwend & Dohrenwend, 1970).

This association between SES and stress ha...

Table of contents

• Cover
• Title
• Copyright
• Contents
• Introduction
• Allostasis and Allostatic Load: Implications for Neuropsychopharmacology
• Oral Administration of a Corticotropin-Releasing Hormone Receptor Antagonist Significantly Attenuates Behavioral, Neuroendocrine, and Autonomic Responses to Stress in Primates
• Hormone Profiles in Humans Experiencing Military Survival Training
• Can Poverty Get under Your Skin? Basal Cortisol Levels and Cognitive Function in Children from Low and High Socioeconomic Status
• Health Inequalities among British Civil Servants: The Whitehall II Study
• Contribution of Job Control and Other Risk Factors to Social Variations in Coronary Heart Disease Incidence
• Maternal Care, Hippocampal Glucocorticoid Receptors, and Hypothalamic-Pituitary-Adrenal Responses to Stress
• Nongenomic Transmission across Generations of Maternal Behavior and Stress Responses in the Rat
• Pituitary-Adrenal and Autonomic Responses to Stress in Women after Sexual and Physical Abuse in Childhood
• Adoption Reverses the Long-Term Impairment in Glucocorticoid Feedback Induced by Prenatal Stress
• Beta-Adrenergic Activation and Memory for Emotional Events
• Stress and Glucocorticoids Impair Retrieval of Long-Term Spatial Memory
• Proliferation of Granule Cell Precursors in the Dentate Gyrus of Adult Monkeys Is Diminished by Stress
• Exposure to Fox Odor Inhibits Cell Proliferation in the Hippocampus of Adult Rats via an Adrenal Hormone-Dependent Mechanism
• Hippocampal Damage Associated with Prolonged Glucocorticoid Exposure in Primates
• Glucocorticoids and Hippocampal Atrophy in Neuropsychiatric Disorders
• Pronounced and Sustained Central Hypernoradrenergic Function in Major Depression with Melancholic Features: Relation to Hypercortisolism and Corticotropin-Releasing Hormone
• Major Depression and the Stress System: A Life Span Perspective
• Psychiatric Disorders among Survivors of the Oklahoma City Bombing
• Longitudinal Study of Psychiatric Symptoms, Disability, Mortality, and Emigration among Bosnian Refugees
• Childhood Trauma and Risk for PTSD: Relationship to Intergenerational Effects of Trauma, Parental PTSD, and Cortisol Excretion
• Allostatic Load as a Marker of Cumulative Biological Risk: MacArthur Studies of Successful Aging
• Successful Aging
• Neural-Immune Interactions in Health and Disease
• The Role of Stress in Drug Self-Administration
• Acknowledgments