Do job stressors affect men and women differently? This question has only recently been addressed in the job stress–illness literature. In fact, the word gender does not even appear in the index of the first edition of the Handbook of Stress (Goldberger and Breznitz 1982) nor does it appear in the indices of such major reference books as Job Stress and Blue Collar Work (Cooper and Smith 1985) and Job Control and Worker Health (Sauter, Hurrell and Cooper 1989). Moreover, in a 1992 review of moderator variables and interaction effects in the occupational stress literature, gender effects were not even mentioned (Holt 1992). One reason for this state of affairs lies in the history of occupational health and safety psychology, which in turn reflects the pervasive gender stereotyping in our culture. With the exception of reproductive health, when researchers have looked at physical health outcomes and physical injuries, they have generally studied men and variations in their work. When researchers have studied mental health outcomes, they have generally studied women and variations in their social roles.

As a result, the “available evidence” on the physical health impact of work has until recently been almost completely limited to men (Hall 1992). For example, attempts to identify correlates of coronary heart disease have been focused exclusively on men and on aspects of their work; researchers did not even inquire into their male subjects’ marital or parental roles (Rosenman et al. 1975). Indeed, few studies of the job stress–illness relationship in men include assessments of their marital and parental relationships (Caplan et al. 1975).

In contrast, concern about reproductive health, fertility and pregnancy focused primarily on women. Not surprisingly, “the research on reproductive effects of occupational exposures is far more extensive on females than on males” (Walsh and Kelleher 1987). With respect to psychological distress, attempts to specify the psychosocial correlates, in particular the stressors associated with balancing work and family demands, have centred heavily on women.

By reinforcing the notion of “separate spheres” for men and women, these conceptualizations and the research paradigms they generated prevented any examination of gender effects, thereby effectively controlling for the influence of gender. Extensive sex segregation in the workplace (Bergman 1986; Reskin and Hartman 1986) also acts as a control, precluding the study of gender as a moderator. If all men are employed in “men’s jobs” and all women are employed in “women’s jobs”, it would not be reasonable to ask about the moderating effect of gender on the job stress–illness relationship: job conditions and gender would be confounded. It is only when some women are employed in jobs that men occupy and when some men are employed in jobs that women occupy that the question is meaningful.

Controlling is one of three strategies for treating the effects of gender. The other two are ignoring these effects or analysing them (Hall 1991). Most investigations of health have either ignored or controlled for gender, thereby accounting for the dearth of references to gender as discussed above and for a body of research that reinforces stereotyped views about the role of gender in the job stress–illness relationship. These views portray women as essentially different from men in ways that render them less robust in the workplace, and portray men as comparatively unaffected by non-workplace experiences.

In spite of this beginning, the situation is already changing. Witness the publication in 1987 of Gender and Stress (Barnett, Biener and Baruch 1987), the first edited volume focusing specifically on the impact of gender at all points in the stress reaction. And the second edition of the Handbook of Stress (Barnett 1992) includes a chapter on gender effects. Indeed, current studies increasingly reflect the third strategy: analysing gender effects. This strategy holds great promise, but also has pitfalls. Operationally, it involves analysing data relating to males and females and estimating both the main and the interaction effects of gender. A significant main effect tells us that after controlling for the other predictors in the model, men and women differ with respect to the level of the outcome variable. Interaction-effects analyses concern differential reactivity, that is, does the relationship between a given stressor and a health outcome differ for women and men?

The main promise of this line of inquiry is to challenge stereotyped views of women and men. The main pitfall is that conclusions about gender difference can still be drawn erroneously. Because gender is confounded with many other variables in our society, these variables have to be taken into account before conclusions about gender can be inferred. For example, samples of employed men and women will undoubtedly differ with respect to a host of work and non-work variables that could reasonably affect health outcomes. Most important among these contextual variables are occupational prestige, salary, part-time versus full-time employment, marital status, education, employment status of spouse, overall work burdens and responsibility for care of younger and older dependants. In addition, evidence suggests the existence of gender differences in several personality, cognitive, behavioural and social system variables that are related to health outcomes. These include: sensation seeking; self-efficacy (feelings of competence); external locus of control; emotion-focused versus problem-focused coping strategies; use of social resources and social support; harmful acquired risks, such as smoking and alcohol abuse; protective behaviours, such as exercise, balanced diets and preventive health regimens; early medical intervention; and social power (Walsh, Sorensen and Leonard, in press). The better one can control these contextual variables, the closer one can get to understanding the effect of gender per se on the relationships of interest, and thereby to understanding whether it is gender or other, gender-related variables that are the effective moderators.

To illustrate, in one study (Karasek 1990) job changes among white-collar workers were less likely to be associated with negative health outcomes if the changes resulted in increased job control. This finding was true for men, not women. Further analyses indicated that job control and gender were confounded. For women, one of “the less aggressive [or powerful] groups in the labour market” (Karasek 1990), white-collar job changes often involved reduced control, whereas for men, such job changes often involved increased control. Thus, power, not gender, accounted for this interaction effect. Such analyses lead us to refine the question about moderator effects. Do men and women react differentially to workplace stressors because of their inherent (i.e., biological) nature or because of their different experiences?

Although only a few studies have examined gender interaction effects, most report that when appropriate controls are utilized, the relationship between job conditions and physical or mental health outcomes is not affected by gender. (Lowe and Northcott 1988 describe one such study). In other words, there is no evidence of an inherent difference in reactivity.

Findings from a random sample of full-time employed men and women in dual-earner couples illustrates this conclusion with respect to psychological distress. In a series of cross-sectional and longitudinal analyses, a matched pairs design was used that controlled for such individual-level variables as age, education, occupational prestige and marital-role quality, and for such couple-level variables as parental status, years married and household income (Barnett et al. 1993; Barnett et al. 1995; Barnett, Brennan and Marshall 1994). Positive experiences on the job were associated with low distress; insufficient skill discretion and overload were associated with high distress; experiences in the roles of partner and parent moderated the relationship between job experiences and distress; and change over time in skill discretion and overload were each associated with change over time in psychological distress. In no case was the effect of gender significant. In other words, the magnitude of these relationships was not affected by gender.

One important exception is tokenism (see, for example, Yoder 1991). Whereas “it is clear and undeniable that there is a considerable advantage in being a member of the male minority in any female profession” (Kadushin 1976), the opposite is not true. Women who are in minority in a male work situation experience a considerable disadvantage. Such a difference is readily understandable in the context of men’s and women’s relative power and status in our culture.

Overall, studies of physical health outcomes also fail to reveal significant gender interaction effects. It appears, for example, that characteristics of work activity are stronger determinants of safety than are attributes of workers, and that women in traditionally male occupations suffer the same types of injury with approximately the same frequency as their male counterparts. Moreover, poorly designed protective equipment, not any inherent incapacity on the part of women in relation to the work, is often to blame when women in male-dominated jobs experience more injuries (Walsh, Sorensen and Leonard, 1995).

Two caveats are in order. First, no one study controls for all the gender-related covariates. Therefore, any conclusions about “gender” effects must be tentative. Secondly, because controls vary from study to study, comparisons between studies are difficult.

As increasing numbers of women enter the labour force and occupy jobs similar to those occupied by men, both the opportunity and the need for analysing the effect of gender on the job stress–illness relationship also increase. In addition, future research needs to refine the conceptualization and measurement of the stress construct to include job stressors important to women; extend interaction effects analyses to studies previously restricted to male or female samples, for example, studies of reproductive health and of stresses due to non-workplace variables; and examine the interaction effects of race and class as well as the joint interaction effects of gender x race and gender x class.

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Major changes are taking place within the workforces of many of the world’s leading industrial nations, with members of ethnic minority groups making up increasingly larger proportions. However, little of the occupational stress research has focused on ethnic minority populations. The changing demographics of the world’s workforce give clear notice that these populations can no longer be ignored. This article briefly addresses some of the major issues of occupational stress in ethnic minority populations with a focus on the United States. However, much of the discussion should be generalizable to other nations of the world.

Much of the occupational stress research either excludes ethnic minorities, includes too few to allow meaningful comparisons or generalizations to be made, or does not report enough information about the sample to determine racial or ethnic participation. Many studies fail to make distinctions among ethnic minorities, treating them as one homogeneous group, thus minimizing the differences in demographic characteristics, culture, language and socio-economic status which have been documented both between and within ethnic minority groups (Olmedo and Parron 1981).

In addition to the failure to address issues of ethnicity, by far the greater part of research does not examine class or gender differences, or class by race and gender interactions. Moreover, little is known about the cross-cultural utility of many of the assessment procedures. Documentation used in such procedures is not adequately translated nor is there demonstrated equivalency between the standardized English and other language versions. Even when the reliabilities appear to indicate equivalence across ethnic or cultural groups, there is uncertainty about which symptoms in the scale are elicited in a reliable fashion, that is, whether the phenomenology of a disorder is similar across groups (Roberts, Vernon and Rhoades 1989).

Many assessment instruments inadequately assess conditions within ethnic minority populations; consequently results are often suspect. For example, many stress scales are based on models of stress as a function of undesirable change or readjustment. However, many minority individuals experience stress in large part as a function of ongoing undesirable situations such as poverty, economic marginality, inadequate housing, unemployment, crime and discrimination. These chronic stressors are not usually reflected in many of the stress scales. Models which conceptualize stress as resulting from the interplay between both chronic and acute stressors, and various internal and external mediating factors, are more appropriate for assessing stress in ethnic minority and poor populations (Watts-Jones 1990).

A major stressor affecting ethnic minorities is the prejudice and discrimination they encounter as a result of their minority status in a given society (Martin 1987; James 1994). It is a well- established fact that minority individuals experience more prejudice and discrimination as a result of their ethnic status than do members of the majority. They also perceive greater discrimination and fewer opportunities for advancement as compared with whites (Galinsky, Bond and Friedman 1993). Workers who feel discriminated against or who feel that there are fewer chances for advancement for people of their ethnic group are more likely to feel “burned out” in their jobs, care less about working hard and doing their jobs well, feel less loyal to their employers, are less satisfied with their jobs, take less initiative, feel less committed to helping their employers succeed and plan to leave their current employers sooner (Galinsky, Bond and Friedman 1993). Moreover, perceived prejudice and discrimination are positively correlated with self-reported health problems and higher blood pressure levels (James 1994).

An important focus of occupational stress research has been the relationship between social support and stress. However, there has been little attention paid to this variable with respect to ethnic minority populations. The available research tends to show conflicting results. For example, Hispanic workers who reported higher levels of social support had less job-related tension and fewer reported health problems (Gutierres, Saenz and Green 1994); ethnic minority workers with lower levels of emotional support were more likely to experience job burn-out, health symptoms, episodic job stress, chronic job stress and frustration; this relationship was strongest for women and for management as opposed to non-management personnel (Ford 1985). James (1994), however, did not find a significant relationship between social support and health outcomes in a sample of African-American workers.

Most models of job satisfaction have been derived and tested using samples of white workers. When ethnic minority groups have been included, they have tended to be African-Americans, and potential effects due to ethnicity were often masked (Tuch and Martin 1991). Research that is available on African-American employees tends to yield significantly lower scores on overall job satisfaction in comparison to whites (Weaver 1978, 1980; Staines and Quinn 1979; Tuch and Martin 1991). Examining this difference, Tuch and Martin (1991) noted that the factors determining job satisfaction were basically the same but that African-Americans were less likely to have the situations that led to job satisfaction. More specifically, extrinsic rewards increase African-Americans’ job satisfaction, but African-Americans are disadvantaged relatively to whites on these variables. On the other hand, blue-collar incumbency and urban residence decrease job satisfaction for African-Americans but African-Americans are overrepresented in these areas. Wright, King and Berg (1985) found that organizational variables (i.e., job authority, qualifications for the position and a sense that advancement within the organization is possible) were the best predictors of job satisfaction in their sample of black female managers in keeping with previous research on primarily white samples.

Ethnic minority workers are more likely than their white counterparts to be in jobs with hazardous work conditions. Bullard and Wright (1986/1987) noted this propensity and indicated that the population differences in injuries are likely to be the result of racial and ethnic disparities in income, education, type of employment and other socio-economic factors correlated with exposure to hazards. One of the most likely reasons, they noted, was that occupational injuries are highly dependent on the job and industry category of the workers and ethnic minorities tend to work in more hazardous occupations.

Foreign workers who have entered the country illegally often experience special work stress and maltreatment. They often endure substandard and unsafe working conditions and accept less than minimum wages because of fear of being reported to the immigration authorities and they have few options for better employment. Most health and safety regulations, guidelines for use, and warnings are in English and many immigrants, illegal or otherwise, may not have a good understanding of written or spoken English (Sanchez 1990).

Some areas of research have almost totally ignored ethnic minority populations. For example, hundreds of studies have examined the relationship between Type A behaviour and occupational stress. White males constitute the most frequently studied groups with ethnic minority men and women almost totally excluded. Available research—e.g., a study by Adams et al. (1986), using a sample of college freshmen, and e.g., Gamble and Matteson (1992), investigating black workers—indicates the same positive relationship between Type A behaviour and self-reported stress as that found for white samples.

Similarly, little research on issues such as job control and work demands is available for ethnic minority workers, although these are central constructs in occupational stress theory. Available research tends to show that these are important constructs for ethnic minority workers as well. For example, African-American licensed practical nurses (LPNs) report significantly less decision authority and more dead-end jobs (and hazard exposures) than do white LPNs and this difference is not a function of educational differences (Marshall and Barnett 1991); the presence of low decision latitude in the face of high demands tends to be the pattern most characteristic of jobs with low socio-economic status, which are more likely to be held by ethnic minority workers (Waitzman and Smith 1994); and middle- and upper-level white men rate their jobs consistently higher than their ethnic minority (and female) peers on six work design factors (Fernandez 1981).

Thus, it appears that many research questions remain regarding ethnic minority populations in the occupational stress and health arena as regards ethnic minority populations. These questions will not be answered until ethnic minority workers are included in study samples and in the development and validation of investigatory instruments.

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Andrew Steptoe and Tessa M. Pollard

The acute physiological adjustments recorded during the performance of problem-solving or psychomotor tasks in the laboratory include: raised heart rate and blood pressure; alterations in cardiac output and peripheral vascular resistance; increased muscle tension and electrodermal (sweat gland) activity; disturbances in breathing pattern; and modifications in gastrointestinal activity and immune function. The best studied neurohormonal responses are those of the catecholamines (adrenaline and noradrenaline) and cortisol. Noradrenaline is the primary transmitter released by the nerves of the sympathetic branch of the autonomic nervous system. Adrenaline is released from the adrenal medulla following stimulation of the sympathetic nervous system, while activation of the pituitary gland by higher centres in the brain results in the release of cortisol from the adrenal cortex. These hormones support autonomic activation during stress and are responsible for other acute changes, such as stimulation of the processes that govern blood clotting, and the release of stored energy supplies from adipose tissue. It is likely that these kinds of response will also be seen during job stress, but studies in which work conditions are simulated, or in which people are tested in their normal jobs, are required to demonstrate such effects.

A variety of methods is available to monitor these responses. Conventional psychophysiological techniques are used to assess autonomic responses to demanding tasks (Cacioppo and Tassinary 1990). Levels of stress hormones can be measured in the blood or urine, or in the case of cortisol, in the saliva. The sympathetic activity associated with challenge has also been documented by measures of noradrenaline spillover from nerve terminals, and by direct recording of sympathetic nervous activity with miniature electrodes. The parasympathetic or vagal branch of the autonomic nervous system typically responds to task performance with reduced activity, and this can, under certain circumstances, be indexed through recording heart rate variability or sinus arrhythmia. In recent years, power spectrum analysis of heart rate and blood pressure signals has revealed wave bands that are characteristically associated with sympathetic and parasympathetic activity. Measures of the power in these wavebands can be used to index autonomic balance, and have shown a shift towards the sympathetic branch at the expense of the parasympathetic branch during task performance.

Few laboratory assessments of acute physiological responses have simulated work conditions directly. However, dimensions of task demand and performance that are relevant to work have been investigated. For example, as the demands of externally paced work increase (through faster pace or more complex problem solving), there is a rise in adrenaline level, heart rate and blood pressure, a reduction in heart rate variability and an increase in muscle tension. In comparison with self-paced tasks performed at the same rate, external pacing results in greater blood pressure and heart rate increases (Steptoe et al. 1993). In general, personal control over potentially stressful stimuli reduces autonomic and neuroendocrine activation in comparison with uncontrollable situations, although the effort of maintaining control over the situation itself has its own physiological costs.

Frankenhaeuser (1991) has suggested that adrenaline levels are raised when a person is mentally aroused or performing a demanding task, and that cortisol levels are raised when an individual is distressed or unhappy. Applying these ideas to job stress, Frankenhaeuser has proposed that job demand is likely to lead to increased effort and thus to raise levels of adrenaline, while lack of job control is one of the main causes of distress at work and is therefore likely to stimulate raised cortisol levels. Studies comparing levels of these hormones in people doing their normal work with levels in the same people at leisure have shown that adrenaline is normally raised when people are at work. Effects for noradrenaline are inconsistent and may depend on the amount of physical activity that people carry out during work and leisure time. It has also been shown that adrenaline levels at work correlate positively with levels of job demand. In contrast, cortisol levels have not been shown typically to be raised in people at work, and it is yet to be demonstrated that cortisol levels vary according to the degree of job control. In the “Air Traffic Controller Health Change Study”, only a small proportion of workers produced consistent increases in cortisol as the objective workload became greater (Rose and Fogg 1993).

Thus only adrenaline among the stress hormones has been shown conclusively to rise in people at work, and to do so according to the level of demand they experience. There is evidence that levels of prolactin increase in response to stress while levels of testosterone decrease. However, studies of these hormones in people at work are very limited. Acute changes in the concentration of cholesterol in the blood have also been observed with increased workload, but the results are not consistent (Niaura, Stoney and Herbst 1992).

As far as cardiovascular variables are concerned, it has repeatedly been found that blood pressure is higher in men and women during work than either after work or during equivalent times of day spent at leisure. These effects have been observed both with self-monitored blood pressure and with automated portable (or ambulatory) monitoring instruments. Blood pressure is especially high during periods of increased work demand (Rose and Fogg 1993). It has also been found that blood pressure rises with emotional demands, for example, in studies of paramedics attending the scenes of accidents. However, it is often difficult to determine whether blood pressure fluctuations at work are due to psychological demands or to associated physical activity and changes in posture. The raised blood pressure recorded at work is especially pronounced among people reporting high job strain according to the Demand-Control model (Schnall et al. 1990).

Heart rate has not been shown to be consistently raised during work. Acute elevations of heart rate may nevertheless be elicited by disruption of work, for example with breakdown of equipment. Emergency workers such as fire-fighters exhibit extremely fast heart rates in response to alarm signals at work. On the other hand, high levels of social support at work are associated with reduced heart rates. Abnormalities of cardiac rhythm may also be elicited by stressful working conditions, but the pathological significance of such responses has not been established.

Gastrointestinal problems are commonly reported in studies of job stress (see “Gastrointestinal problems” below). Unfortunately, it is difficult to assess the physiological systems underlying gastrointestinal symptoms in the work setting. Acute mental stress has variable effects on gastric acid secretion, stimulating large increases in some individuals and reduced output in others. Shift workers have a particularly high prevalence of gastrointestinal problems, and it has been suggested that these may arise when diurnal rhythms in the central nervous system’s control of gastric acid secretion are disrupted. Anomalies of small bowel motility have been recorded using radiotelemetry in patients diagnosed with irritable bowel syndrome while they go about their everyday lives. Health complaints, including gastrointestinal symptoms, have been shown to co-vary with perceived workload, but it is not clear whether this reflects objective changes in physiological function or patterns of symptom perception and reporting.

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Researchers may disagree on the meaning of the term stress. However, there is a basic agreement that perceived work-related stress may be implicated in behavioural outcomes such as absenteeism, substance abuse, sleep disturbances, smoking and caffeine use (Kahn and Byosiere 1992). Recent evidence supporting these relationships is reviewed in this chapter. Emphasis is placed upon the aetiological role of work-related stress in each of these outcomes. There are qualitative differences, along several dimensions, among these outcomes. To illustrate, in contrast to the other behavioural outcomes, which are all considered problematic to the health of those engaging in them excessively, absenteeism, while detrimental to the organization, is not necessarily harmful to those employees who are absent from work. There are, however, common problems in the research on these outcomes, as discussed in this section.

The varying definitions of work-related stress have already been mentioned above. By way of illustration, consider the different conceptualizations of stress on the one hand as events and on the other as chronic demands at the workplace. These two approaches to stress measurement have seldom been combined in a single study designed to predict the sorts of behavioural outcome considered here. The same generalization is relevant to the combined use, in the same study, of family-related and work-related stress to predict any of these outcomes. Most of the studies referred to in this chapter were based on a cross-sectional design and employees’ self-reports on the behavioural outcome in question. In most of the research that concerned behavioural outcomes of work-related stress, the joint moderating or mediating roles of predisposing personality variables, like the Type A behaviour pattern or hardiness, and situational variables like social support and control, have hardly been investigated. Seldom have antecedent variables, like objectively measured job stress, been included in the research designs of the studies reviewed here. Finally, the research covered in this article employed divergent methodologies. Because of these limitations, a frequently encountered conclusion is that the evidence for work-related stress as a precursor of a behavioural outcome is inconclusive.

Beehr (1995) considered the question of why so few studies have systematically examined the associations between work- related stress and substance abuse. He argued that such neglect may be due in part to the failure of researchers to find these associations. To this failure, one should add the well-known bias of periodicals against publishing research that reports null results. To illustrate the inconclusiveness of the evidence linking stress and substance abuse, consider two large-scale national samples of employees in the United States. The first, by French, Caplan and Van Harrison (1982), failed to find significant correlations between types of work-related stress and either smoking, drug use or on-the-job caffeine ingestion. The second, an earlier research study by Mangione and Quinn (1975), did report such associations.

The study of the behavioural outcomes of stress is further complicated because they frequently appear in pairs or triads. Different combinations of outcomes are the rule rather than the exception. The very close association of stress, smoking and caffeine is alluded to below. Yet another example concerns the comorbidity of post-traumatic stress disorder (PTSD), alcoholism and drug abuse (Kofoed, Friedman and Peck 1993). This is a basic characteristic of several behavioural outcomes considered in this article. It has led to the construction of “dual diagnosis” and “triple diagnosis” schemes and to the development of comprehensive, multifaceted treatment approaches. An example of such an approach is that in which PTSD and substance abuse are treated simultaneously (Kofoed, Friedman and Peck 1993).

The pattern represented by the appearance of several outcomes in a single individual may vary, depending on background characteristics and genetic and environmental factors. The literature on stress outcomes is only beginning to address the complex questions involved in identifying the specific pathophysiological and neurobiological disease models leading to different combinations of outcome entities.

Smoking Behaviour

A large body of epidemiological, clinical and pathological studies relates cigarette smoking to the development of cardiovascular heart disease and other chronic diseases. Consequently, there is a growing interest in the pathway leading from stress, including stress at work, to smoking behaviour. Stress, and the emotional responses associated with it, anxiety and irritability, are known to be attenuated by smoking. However, these effects have been shown to be short-lived (Parrott 1995). Impairments of mood and affective states tend to occur in a repetitive cycle between each cigarette smoked. This cycle provides a clear pathway leading to the addictive use of cigarettes (Parrott 1995). Smokers, therefore, obtain only a short-lived relief from adverse states of anxiety and irritability that follow the experience of stress.

The aetiology of smoking is multifactorial (like most other behavioural outcomes considered here). To illustrate, consider a recent review of smoking among nurses. Nurses, the largest professional group in health care, smoke excessively compared with the adult population (Adriaanse et al. 1991). According to their study, this is true for both male and female nurses, and is explained by work stress, lack of social support and unmet expectations that characterize nurses’ professional socialization. Nurses’ smoking is considered a special public health problem since nurses often act as role models to patients and their families.

Smokers who express high motivation to smoke have reported, in several studies, above-average stress that they had experienced before smoking, rather than below-average stress after smoking (Parrott 1995). Consequently, stress management and anxiety reduction programmes in the workplace do have the potential of influencing motivation for smoking. However, workplace-based smoking-cessation programmes do bring to the fore the conflict between health and performance. Among aviators, as an example, smoking is a health hazard in the cockpit. However, pilots who are required to abstain from smoking during and before flights may suffer cockpit performance decrements (Sommese and Patterson 1995).

Drug and Alcohol Abuse

A recurrent problem is that often researchers do not distinguish between drinking and problem-drinking behaviour (Sadava 1987). Problem-drinking is associated with adverse health or performance consequences. Its aetiology has been shown to be associated with several factors. Among them, the literature refers to prior incidents of depression, lack of supportive family environment, impulsiveness, being female, other concurrent substance abuse and stress (Sadava 1987). The distinction between the simple act of drinking alcohol and problem drinking is important because of the current controversy on the reported beneficial effects of alcohol on low density lipoprotein (LDL) cholesterol and on the incidence of heart disease. Several studies have shown a J-shaped or U-shaped relationship between alcohol ingestion and the incidence of cardiovascular heart disease (Pohorecky 1991).

The hypothesis that people ingest alcohol even in an incipiently abusive pattern to reduce stress and anxiety is no longer accepted as adequate. Contemporary approaches to alcohol abuse view it as determined by processes set forth in a multifactorial model or models (Gorman 1994). Among risk factors for alcohol abuse, recent reviews refer to the following factors: sociocultural (i.e., whether alcohol is readily available and its use tolerated, condoned or even promoted), socio-economic (i.e., the price of alcohol), environmental (alcohol advertising and licensing laws affect the consumers’ motivation to drink), interpersonal influences (such as family drinking habits), and employment-related factors, including stress at work (Gorman 1994). It follows that stress is but one of several factors in a multidimensional model that explains alcohol abuse.

The practical consequence of the multifactorial model view of alcoholism is the decrease in the emphasis on the role of stress in the diagnosis, prevention and treatment of substance abuse in the workplace. As noted by a recent review of this literature (Peyser 1992), in specific job situations, such as those illustrated below, attention to work-related stress is important in formulating preventive policies directed at substance abuse.

Despite considerable research on stress and alcohol, the mechanisms that link them are not entirely understood. The most widely accepted hypothesis is that alcohol disrupts the subject’s initial appraisal of stressful information by constraining the spread of activation of associated information previously stored in long-term memory (Petraitis, Flay and Miller 1995).

Work organizations contribute to and may induce drinking behaviour, including problem drinking, by three basic processes documented in the research literature. First, drinking, abusive or not, may be affected by the development of organizational norms with respect to drinking on the job, including the local “official” definition of problem drinking and the mechanisms for its control established by management. Secondly, some stressful working conditions, like sustained overload or machine-paced jobs or the lack of control may produce alcohol abuse as a coping strategy alleviating the stress. Thirdly, work organizations may explicitly or implicitly encourage the development of occupationally based drinking subcultures, such as those that often emerge among professional drivers of heavy vehicles (James and Ames 1993).

In general, stress plays a different role in provoking drinking behaviour in different occupations, age groups, ethnic categories and other social groupings. Thus stress probably plays a predisposing role with respect to alcohol consumption among adolescents, but much less so among women, the elderly and college-age social drinkers (Pohorecky 1991).

The social stress model of substance abuse (Lindenberg, Reiskin and Gendrop 1994) suggests that the likelihood of employees’ drug abuse is influenced by the level of environmental stress, social support relevant to the experienced stress, and individual resources, particularly social competence. There are indications that drug abuse among certain minority groups (like Native American youth living on reservations: see Oetting, Edwards and Beauvais 1988) is influenced by the prevalence of acculturation stress among them. However, the same social groups are also exposed to adverse social conditions like poverty, prejudices and impoverished opportunities for economic, social and educational opportunities.

Caffeine Ingestion

Caffeine is the most widely consumed pharmacologically active substance in the world. The evidence bearing upon its possible implications for human health, that is whether it has chronic physiological effects on habitual consumers, is as yet inconclusive (Benowitz 1990). It has long been suspected that repeated exposure to caffeine may produce tolerance to its physiological effects (James 1994). The consumption of caffeine is known to improve physical performance and endurance during prolonged activity at submaximal intensity (Nehlig and Debry 1994). Caffeine’s physiological effects are linked to the antagonism of adenosine receptors and to the increased production of plasma catecholamines (Nehlig and Debry 1994).

The study of the relationship of work-related stress on caffeine ingestion is complicated because of the significant inter-dependance of coffee consumption and smoking (Conway et al. 1981). A meta-analysis of six epidemiological studies (Swanson, Lee and Hopp 1994) has shown that about 86% of smokers consumed coffee while only 77% of the non-smokers did so. Three major mechanisms have been suggested to account for this close association: (1) a conditioning effect; (2) reciprocal interaction, that is, caffeine intake increases arousal while nicotine intake decreases it and (3) the joint effect of a third variable on both. Stress, and particularly work-related stress, is a possible third variable influencing both caffeine and nicotine intake (Swanson, Lee and Hopp 1994).

Sleep Disturbances

The modern era of sleep research began in the 1950s, with the discovery that sleep is a highly active state rather than a passive condition of nonresponsiveness. The most prevalent type of sleep disturbance, insomnia, may occur in a transient short-term form or in a chronic form. Stress is probably the most frequent cause of transient insomnia (Gillin and Byerley 1990). Chronic insomnia usually results from an underlying medical or psychiatric disorder. Between one-third and two-thirds of patients with chronic insomnia have a recognizable psychiatric illness (Gillin and Byerley 1990).

One of the mechanisms suggested is that the effect of stress on sleep disturbances is mediated via certain changes in the cerebral system at different levels, and changes in the biochemical body functions that disturb the 24-hour rhythms (Gillin and Byerley 1990). There is some evidence that the above linkages are moderated by personality characteristics, such as the Type A behaviour pattern (Koulack and Nesca 1992). Stress and sleep disturbances may reciprocally influence each other: stress may promote transient insomnia, which in turn causes stress and increases the risk of episodes of depression and anxiety (Partinen 1994).

Chronic stress associated with monotonous, machine-paced jobs coupled with the need for vigilance—jobs frequently found in continuous-processing manufacturing industries—may lead to sleep disturbances, subsequently causing decrements in performance (Krueger 1989). There is some evidence that there are synergetic effects among work-related stress, circadian rhythms and reduced performance (Krueger 1989). The adverse effects of sleep loss, interacting with overload and a high level of arousal, on certain important aspects of job performance have been documented in several studies of sleep deprivation among hospital doctors at the junior level (Spurgeon and Harrington 1989).

The study by Mattiason et al. (1990) provides intriguing evidence linking chronic job stress, sleep disturbances and increases in plasma cholesterol. In this study, 715 male shipyard employees exposed to the stress of unemployment were systematically compared with 261 controls before and after the economic instability stress was made apparent. It was found that among the shipyard employees exposed to job insecurity, but not among the controls, sleep disturbances were positively correlated with increases in total cholesterol. This is a naturalistic field study in which the period of uncertainty preceding actual layoffs was allowed to elapse for about a year after some employees received notices concerning the impending layoffs. Thus the stress studied was real, severe, and could be considered chronic.

Absenteeism

Absence behaviour may be viewed as an employee coping behaviour that reflects the interaction of perceived job demands and control, on the one hand, and self-assessed health and family conditions on the other. Absenteeism has several major dimensions, including duration, spells and reasons for being absent. It was shown in a European sample that about 60% of the hours lost to absenteeism were due to illness (Ilgen 1990). To the extent that work-related stress was implicated in these illnesses, then there should be some relationship between stress on the job and that part of absenteeism classified as sick days. The literature on absenteeism covers primarily blue-collar employees, and few studies have included stress in a systematic way. (McKee, Markham and Scott 1992). Jackson and Schuler’s meta-analysis (1985) of the consequences of role stress reported an average correlation of 0.09 between role ambiguity and absence and -0.01 between role conflict and absence. As several meta-analytic studies of the literature on absenteeism show, stress is but one of many variables accounting for these phenomena, so we should not expect work-related stress and absenteeism to be strongly correlated (Beehr 1995).

The literature on absenteeism suggests that the relationship between work-related stress and absenteeism may be mediated by employee-specific characteristics. For example, the literature refers to the propensity to use avoidance coping in response to stress at work, and to being emotionally exhausted or physically fatigued (Saxton, Phillips and Blakeney 1991). To illustrate, Kristensen’s (1991) study of several thousand Danish slaughterhouse employees over a one-year period has shown that those who reported high job stress had significantly higher absence rates and that perceived health was closely associated with absenteeism due to illness.

Several studies of the relationships between stress and absenteeism provide evidence that supports the conclusion that they may be occupationally determined (Baba and Harris 1989). To illustrate, work-related stress among managers tends to be associated with the incidence of absenteeism but not with days lost attributed to illness, while this is not so with shop-floor employees (Cooper and Bramwell 1992). Occupational specificity of the stresses predisposing employees to be absent has been regarded as a major explanation of the meagre amount of absence variance explained by work-related stress across many studies (Baba and Harris 1989). Several studies have found that among blue-collar employees who work on jobs considered stressful—that is those that possess a combination of the characteristics of assembly-line type of jobs (namely, a very short cycle of operations and a piece-rate wage system)—job stress is a strong predictor of unexcused absence. (For a recent review of these studies, see McKee, Markham and Scott 1992; note that Baba and Harris 1989 do not support their conclusion that job stress is a strong predictor of unexcused absence).

The literature on stress and absenteeism provides a convincing example of a limitation noted in the introduction. The reference is to the failure of most research on stress-behavioural outcome relations to cover systematically, in the design of this research, both work and non-work stresses. It was noted that in research on absenteeism non-work stress contributed more than work-related stress to the prediction of absence, lending support to the view that absence may be non-work behaviour more than work-related behaviour (Baba and Harris 1989).

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