Occupational Health

In this article a brief historical background of the development of social and psychological working conditions is followed by a description of the presently most widely utilized theoretical models for studying the psychosocial work environment in research and practice, the ‘person–environment (PE) fit,’ ‘demand–control–support,’ ‘organizational justice’ and ‘effort– reward’ models. Possibilities and difficulties in assessment are discussed. It is pointed out that both ‘objective’ and ‘subjective’ aspects are important and that these are not always strongly correlated. Physiological models linking the psychosocial models to health and disease are discussed and finally experiences of interventions are discussed. The main conclusion is that it is possible to define and assess psychosocial factors at work, that such factors are linked to physiological mechanisms, and that interventions based upon them are possible.

Introduction: Work and Health

During historical periods preceding industrialization, most of the work that humans were involved in was unpaid. The borders between work and leisure were not clear. It was with industrialism that paid work started to play such an important role in human life. For several generations, paid work has been the activity that has generated a family’s needs for survival.

Health is not only the absence of illness. It is also a positive state in its own right. However, most of the research that has been published regarding work and health has been devoted to the establishment of relationships between certain adverse working conditions and illness. Accordingly, most of this article will be on work–illness relationships. But we shall also discuss possible pathways between good working conditions and the promotion of health.

An important basis for our understanding of the effects of working conditions on health has been the physiological stress research which was initiated by Hans Selye (1976). Initially stress researchers studied acute reactions to energy-demanding situations. Subsequently, they examined the biological consequences of long-lasting adverse life situations.

The Physiological Basis of the Effects of Work on Health

Genetic evolution and selection processes are slow. Therefore our biological reactions to stressful situations are likely to be approximately the same as they used to be several thousand years ago. It has been emphasized by many authors (Levi, 1972; Frankenhaeuser, 1980) that this may not be functional for man in modern societies and especially not at work where physical demands are becoming less and less important. It was functional for the primitive human being who needed to face dangerous animals to become strong, courageous, and insensitive to physical pain. However, most contemporary dangers have to do with complicated social interactions and in such situations the mobilization of physical energy is not functional. It is possible to regard some adverse aspects of lifestyle, such as smoking, the use of drugs stimulating the central nervous system, and the consumption of sweets and alcohol as ‘external’ efforts to cope with energy-demanding situations.

Energy Mobilization and Anabolism at Work

In Selye’s (1976) general adaptation syndrome, ‘stress’ was seen as the general reaction to a nonspecific challenge or adverse condition. The situation that induced stress was labeled a stressor (factor which induces stress). Since it has central importance to the understanding of stress at work, a short description of energy mobilization will be given here. The most important biological process is the provision of energy – glucose and free fatty acids enter the blood and are used for the immediate production of energy. But there are several parallel phenomena, all of which aid the body in physical fight or flight responses. Examples are lowered excretion of water and salt, decreased sensitivity to pain, and decreased inflammatory responses to infections. Since energy mobilization (resulting in elevated blood concentration of glucose and free fatty acid) has the highest priority, anabolism (restorative and regenerative activities in the cells) is downregulated. Anabolism is central to the body’s central defense of all the organ systems that need constant rebuilding and restoration. If this goes on for a long time (several months) increased sensitivity to physical and psychological stress in bodily organs is the ultimate result. There is a balance between regulation of energy mobilization and anabolism. There are two parallel regulatory systems ranging from the hypothalamus to the pituitary and to their respective endocrine organs, namely the hypothalamo– pituitary–adrenocortical (HPA axis) and the hypothalamo– pituitary–gonadal (HPG axis) systems. While the HPA axis facilitates energy mobilization, the HPG axis facilitates regeneration and reproduction. In many situations they counteract one another. For instance, during long periods of excessive arousal and effort the HPG axis is inhibited. But on the other hand, high HPG axis activity may protect the body against the adverse effects of long-lasting, excessive HPA axis activity (Theorell, 2012). This has importance in the work environment in the sense that the psychosocial processes that stimulate the HPG axis may also protect against adverse effects of a stressful work environment.

Another consequence of long-lasting demands for energy mobilization is that the endocrine systems may change their regulatory patterns. This means that the ability of the body to stop energy mobilization when it is no longer needed may be disturbed or that the counter-regulation (inhibition of energy mobilization) is inhibited. Most processes in the body have a counter-regulatory mechanism that operates in order to inhibit a process that has been stimulated.

Physiological Short-Term and Long-Term Adaptation to Requirements at Work

The HPA axis is of central importance to the biological arousal mechanism. The steroid hormone cortisol which is released from the adrenal cortex is the most extensively studied ‘agent’ in this system. Cortisol facilitates biological arousal in most organ systems. Disturbed regulation of the HPA axis has been described as a possible consequence of long-lasting arousal. There are at least three kinds of such regulatory disturbances in the HPA axis, all of which are of relevance to health at work:

1. Lack of inhibition of arousal. All reactions in the body evoke counter-regulatory reactions. This is true also of energy mobilization, which should stop when the threat disappears. Normally cortisol inhibits higher centers in the HPA axis when it has been in the aroused state for some time. When this inhibition does not take place in the normal way, the levels tend to become constantly elevated.
2. Lack of response to stimulation of the HPA axis. This means that plasma cortisol levels are low and that normal activation does not take place when the HPA axis is stimulated artificially. This has often been labeled the ‘flat cortisol curve.’ This refers to the fact that the circadian variation is small and the ‘awakening response’ (the normal increase in cortisol levels from awakening until half an hour later, which could be regarded as a kind of stress response) is attenuated.
3. Unstable levels. In this kind of disturbance the plasma cortisol levels may be low at rest, but certain situations – that are specific to the individual and have to do with the symbolic significance of the event – trigger a strong HPA axis reaction that may seem to be out of proportion to the importance of the trigger. This occurs in subjects who have been exposed to extraordinarily stressful situations, such as torture, war, disasters, and incest.

The first kind of regulatory disorder (1) is typical of Cushing’s syndrome (overproduction of corticosteroids including cortisol due to a disease in the adrenal cortex) and could be one alternative regulatory disturbance in clinically severe psychiatric depression. In patients hospitalized for severe psychiatric depression a pattern with constantly high cortisol levels was observed (Rubin et al., 1987). This pattern has become less prevalent with the frequent use of antidepressive medication in the population. Currently, in epidemiological studies of the relationship between cortisol excretion and depression, it is mostly not observed (see for instance Alderling et al., 2008).

The second kind (2) has been shown to exist in a subgroup of patients with the diagnosis of chronic fatigue syndrome or CFS (Demitrack et al., 1991). Conditions with long-lasting fatigue as a prominent feature, for instance the burnout syndrome, have been shown to be associated with poor awakening response, which is correlated with the ‘flat cortisol curve’ (Chida and Steptoe, 2009; Halford et al., 2012).

The third kind of regulatory disorder (3) is found in posttraumatic stress disorder (PTSD) (Charney et al., 1993). The key element in the etiology of PTSD seems to be that the long-lasting extreme arousal level increases the number of cortisol receptors on the cell surfaces and also increases their sensitivity. Since the sensitivity is high, only low concentrations of cortisol are needed to keep the system working at rest. This may be the reason why low serum cortisol levels are found at rest in patients with PTSD.

It is important to consider these different forms of regulatory disturbance in working subjects. Men and women with severe such regulatory disturbances are mostly unable to work and mild disturbance causes disturbed ability to cope with working tasks.

Unemployment and Stress

Unemployment is a common phenomenon in all industrialized countries. In most European countries it is presently of the order of 10%. Research has tried to establish the extent to which unemployment contributes to poor health. At present there is agreement that poor health increases the risk of becoming unemployed in periods of financial crisis but there is also agreement that unemployment per se contributes to poor health. Longitudinal studies of subjects who have gone through the different stages of unemployment (Brenner and Levi, 1987) or started activities again after a long period of unemployment have shown that several physiological systems are markedly affected by these processes. For instance, there is elevation of the secretion of cortisol (an index of energy mobilization) and prolactin (which mirrors passiveness in a crisis situation). It is accordingly reasonable to assume that health could be affected. There is published research showing that long-lasting unemployment increases the risk of mental disorder (Hallsten, 1998) and is also associated with a lifestyle that increases the risk of developing cardiovascular disease, particularly in young people (Janlert et al., 1991; Janlert and Hammarstrom, 1991). Economic hardship may add to the health consequences (Vinokur et al., 1996). Downsizing is associated with increased prevalence of poor mental health (emotional exhaustion and depression) not only for the dismissed workers but also for those remaining as workers in the ‘downsized’ workplace. A recent study of the situation in Hungary, Sweden, and France showed that the relationship between downsizing and poor mental health is particularly pronounced in Hungary where societal and financial support systems are weaker than in the other studied countries. In addition, studies show that subjects who remain employed after dismissal of colleagues in their workplace may also suffer from mental symptoms and that the way in which management handles downsizing is crucial for the mental health of the employees (European Commission, 2011). Not unexpectedly, a well-organized downsizing process with good information and understandable goals does not result in as much health deterioration among employees as a chaotic, poorly organized downsizing process resulting in a less effective organization.

Jahoda (1979) formulated the basic reasons why work is such an important activity in modern life – the most central one being that work provides structure to life. There is extensive research showing that organized support can help the unemployed to regain employment (Vinokur et al., 1995). Evaluation of such programs, however, also shows that these programs may increase passiveness and feelings of low self-esteem if the initiative of the individual is taken away.

Combined Effects of Physical and Psychosocial Adversities at Work

Extensive research has been devoted to the disentanglement of physical stress from psychological stress in studies of health and disease. For instance, in the study of the importance of ergonomic load to the development of musculoskeletal disorders, it has been considered important to adjust for psychological stress. Extensive epidemiological studies of large samples of subjects have shown that ergonomic load contributes to the development of musculoskeletal disorder but that psychosocial factors at work may also contribute significantly (Kilbom et al., 1996). It has been shown that combinations of physical ergonomic and psychosocial factors may be of particular importance to low back pain (Vingard et al., 2000). The potential importance of the combination of noise exposure and job strain has also been documented in relation to morning cortisol excretion (Selander et al., 2012). Furthermore there seems to be an interaction between long-term symptoms of prolonged adverse stress (burnout syndrome, see above) and the ability to cope with a combination of acute stress and unpleasant sound, particularly among female working subjects. A study was based upon screening of working subjects with high scores on emotional exhaustion. Emotionally exhausted subjects showed lowered noise thresholds after acute experimental stress whereas normal subjects showed elevated thresholds. In other words, the normal way of coping with a combination of acute stress and noise is to elevate the noise tolerance whereas exhausted subjects become more sensitive to noise when there is acute stress (Hasson et al., 2013).

It has been important for the study of relationships between working conditions and health to have theoretical models that form the basis for hypothesis testing. The interplay between the individual and the environment has been an important point of departure in all theoretical modeling in this field. Some of the models have focused on environmental aspects – for instance, the demand–control and organizational justice models – and some on individual aspects, for instance, the eustress–distress model. The person–environment (PE) fit and the effort–reward imbalance models are other examples of models taking the interaction between the individual and the environment into account. These four models will be described briefly below.

Theoretical Models for the Study of Work and Health – Individual or Environment

The individual’s response to demanding work situations has been the point of departure for Frankenhaeuser and her coworkers (Frankenhaeuser, 1980) who introduced one of the most influential models, the eustress–distress model. According to this model, the individual responds to the work situation with different degrees of effort. The bodily reactions to a high degree of effort are influenced by the concomitant degree of joy or distress in the situation. High effort with joy is labeled eustress while high effort with marked distress corresponds to a negative stress reaction.

The environmental counterpart of the effort–distress model is the demand–control model that has been used extensively. Accordingly this will be described in more detail. Karasek introduced the ‘demand–control’ model. It is a two-dimensional synthesis of the demand (‘stress psychological’) and the ‘lack of control’ (sociological) research traditions (Karasek and Theorell, 1990; Karasek, 1979). Lack of control has two components: ‘Skill utilization’ is related to the employee’s control over the use and development of his/her skills, whereas ‘authority over decisions’ is related to the employee’s control over decision-making relevant to his/her work tasks. The two factors are mostly added to one another to constitute ‘decision latitude.’

The other dimension in the original demand–control model, psychological demands, includes both quantitative (how much work per time unit) and qualitative demands. Qualitative demands can be subdivided for instance into cognitive and emotional demands and demands to control one’s emotions as in some kinds of health care work (Pejtersen et al., 2010). It has been claimed that different kinds of demands, for instance the ones related to intensity and to the number of working hours (extensiveness) should be treated separately for different groups of employees (Kristensen et al., 2004).

The high demand–low decision latitude combination, job strain, is regarded as the most dangerous in the development of illness. According to the theory, this kind of situation, if prolonged and repeated for a long time, increases sympathoadrenal arousal and at the same time decreases anabolism, the body’s ability to restore and repair tissues (Karasek and Theorell, 1990).

The combination of high psychological demands and high decision latitude is defined as the active situation. In this situation, the worker should be given more resources to cope with high psychological demands so that he/she can make relevant decisions, such as planning working hours according to his/her own biological rhythm. In addition he/she gets good possibilities to improve coping strategies – facilitating feelings of mastery and control in unforeseen situations. This situation corresponds to psychological growth.

The low demand–high decision latitude situation is the relaxed and theoretically ideal one, whereas the low demand– low decision latitude situation, which is labeled passive, may be associated with risk of loss of skills and, to some extent, psychological capacity.

It soon became evident that a third component, social support, was needed in the demand–control model. This dimension had already been introduced previously in job stress research (House, 1981). Johnson has discussed this component extensively. He has pointed out that collective support may be difficult to separate theoretically from collective control. Workers who are exposed to adverse working conditions may join forces and increase their control over their working conditions. The worst hypothesized situation is ‘iso-strain’ – job strain and lack of social support (Johnson et al., 1989).

There is a striking difference between the effort–distress model and the demand–control model. Whereas the former is designed to explain differences in individual response to stressors, the latter is designed to assess the environmental conditions, – the stressors. There is of course a relationship between the models since eustress reactions are likely be more common in the ‘active job’ situation and negative stress reactions more common in the ‘job strain’ situation.

Interaction Between Individual and Environment

One of the most influential models has been that of the Michigan school, the PE fit model (Katz and Kahn, 1966). This theory postulates that adverse reactions at work arise when the PE fit is poor. In this model the interaction between a person’s characteristics and the environment is the central theme. If the characteristics of the job do not fit the characteristics of the person there is a high likelihood that negative stress reactions may arise. There is considerable empirical support for this hypothesis (Kahn, 1981). Another important theme is the expectation of the person – those who have very positive expectations may be more disappointed than those who have negative expectations, if the conditions do not fit. The Michigan school also added social support at work as a central theme (House, 1981).

According to Siegrist (1996), a crucial job factor for health consequences is the degree to which the workers are rewarded for their efforts. When a high degree of effort does not meet a high degree of reward, emotional tensions arise and risk of illness increases. It is a sociological theory that includes individual aspects. The effort component includes environmental (extrinsic effort, which is close to ‘psychological demands’ in the demand– control model) as well as individual aspects (intrinsic effort, overcommitment). A high degree of overcommitment could be the result of previous job experiences as well as of other experiences in the person’s life. The reward component includes three different aspects of reward, namely monetary reward, promotion possibilities, and self-esteem. The construction of the questions specifically addresses whether the individual sees, for instance, a specific kind of extrinsic effort as a problem or not.

A more recent theoretical model related to the previous ones is the ‘demand–resource’ model (Demerouti et al., 2001). It is similar to the demand–control model, but it incorporates both individual and environmental resources. Whereas the demand–control model tries to focus on the organizational aspects of work, the demand–resource model has a mixed focus.

‘Organizational justice’ is another basic concept that has been used in job stress research. This concept builds upon the idea that job sites must have a system/organization for resolving conflicts and that this is important for employee health. It has also proved to be useful in illness prediction (Kivimaki et al., 2006).

Several multidimensional standardized questionnaires for the measurement of stressors and stress reactions at work have been published. The most extensively used one is the Occupational Stress Indicator (OSI), (Cooper and Payne, 1978; Cooper et al., 1988) that is based partly on the PE fit model and incorporates all of the dimensions in psychosocial work conditions.

During later years, considerable efforts have been made to explore the relationship between theoretical job stress models and ‘hard endpoints’ for health development. Previously scientific literature was criticized because most of the relationships had been observed in studies using self-reports both in descriptions of the stressors and the health outcomes (Kasl, 1982). There may be a risk in such studies that a pattern of complaining may affect both explaining variables and health outcomes. Therefore, studies have included prospective designs as well as objective outcomes (such as myocardial infarction or cardiac death) and objective recordings of stressors at work (through population means for each occupation regarding decision latitude, for instance; or by means of expert ratings of the crucial stressors). The demand–control model has been more extensively studied than the other models from this point of view.

Job Stress Models and Disease

The significance of the demand–control–support model to cardiovascular disease, in particular high blood pressure and myocardial infarction (Schnall et al, 1990; Theorell and Karasek, 1996; Melamed et al., 1998), has been tested in many epidemiological case-control as well as prospective studies. There is considerable support for the hypothesis that the combination of high demands and lack of control is associated with increased risk of developing myocardial infarction before retirement age. A recently published European study of a pooled cohort of almost 200 000 working men and women, showed a significant association between exposure to the combination of high psychological demands (above median for the demand scale) and low decision latitude (below median), and increased risk of developing a myocardial infarction during follow-up (Kivimaki et al., 2012). There were similar findings for men and women and they were robust when adjusted for age, other risk factors, and publication bias. The combination of high demands and low decision latitude was a better predictor than either demands or decision latitude separately. This study has been criticized because of the relatively weak exposure assessment with few questions assessing demand and decision latitude respectively. In addition, there was only one assessment of job strain before the follow-up started. It has been shown that predictions gain precision if the exposure to job stress is assessed several times during the follow-up period, since participants experience changing work situations. It is therefore likely that the reported job strain-related myocardial infarction risk in the European pooled study (1.2 or 1.3) is lower than the true risk. In the early studies of demand and decision latitude in relation to myocardial infarction risk, the decision latitude was more important than the demand dimension but during recent years the opposite has been found to be true, possibly reflecting a changing working life (Eller et al., 2009). Loss of decision latitude has also been shown to be associated with increased risk of developing a first myocardial infarction in the near future, even after adjustment for other risk factors (Theorell et al., 1998). The support dimension has been less extensively studied than demand and control, but ‘iso-strain,’ – the combination of poor workplace support and job strain – has been shown to be associated with an increased development of the metabolic syndrome, which is a biological long-term consequence of adverse psychosocial stress and also a condition which increases the risk of developing cardiovascular disease (Chandola et al., 2010).

High blood pressure monitored during activities at work has shown a convincing relationship with job strain (Schnall et al., 1990; Laflamme et al., 1998; Riese et al., 2004). Serum lipids and smoking patterns have not shown consistent relationships with job strain (Theorell et al., 1998). Accelerated blood coagulation and activation of proinflammatory cytokines may be mechanisms that operate in the relationship between job strain and myocardial infarction risk, since studies have shown that high plasma fibrinogen (Tsutsumi et al., 1999; Brunner et al., 1996) and interleukin-6 (Theorell et al., 2000) are associated with low decision latitude and/or job strain.

Variations over time in job strain have been shown to be associated with changes in endocrine parameters and immune system function of relevance to stress theory. For instance, in one study of men, plasma testosterone (which is important to anabolism) decreased and immunoglobulin G increased (indicating increased immune system activity) when job strain increased and vice versa (Theorell et al., 1990a,b). In another study plasma testosterone increased when the total working life situation improved (Grossi et al., 1999).

Studies of the effort–reward model in relation to coronary heart disease (CHD) and its risk factors have also shown convincing relationships. A review by Kivimaki et al. (2006) showed that in men the CHD risk associated with effort– reward imbalance may even be more pronounced than the risk observed for job strain. High blood pressure and atherogenic lipids are associated with effort–reward imbalance. The patterns of association are different for men and women (Peter et al., 1998; Siegrist, 1996).

The PE fit model and related models have been used in studies of cardiovascular risk factors and positive findings have been reported (Cooper and Payne, 1978).

Musculoskeletal disorders such as low back pain and neck– shoulder pain have also been studied in relation to the demand–control model. The findings have been mixed. The relationships depend on the group and the kind of disorder studied. In some studies, social support at work is crucial whereas in others psychological demands or decision latitude may be important. When the associations between musculoskeletal disorder and psychosocial work environment are adjusted for physical load, the associations are often weakened. Among female workers, physical load and adverse psychosocial conditions are frequently correlated (Josephson et al., 1999). Vingard et al. (2000) showed that the prediction of the risk of developing an acute episode of low back pain is improved by combining psychosocial and physical working conditions. Similar findings have been made for neck–shoulder pain episodes (Wigaeus Tornqvist et al., 2001).

Integration of Effort–Reward Imbalance and Demand–Control

There is evidence (Bosma et al., 1998) that the decision latitude component of the demand–control model and the effort–reward imbalance model are contributing independently of one another to the prediction of episodes of CHD. Peter et al. (2002) found that a combination of the effort– reward and demand–control models provided better prediction of myocardial infarction risk than either one separately and also that the patterns were different for men and women. These findings confirm that the models are related to different psychosocial mechanisms linking psychosocial working conditions to health outcome. The models have psychological demands (extrinsic effort) in common but control (decision latitude) and reward are clearly different. A logical step would be to combine the models. Even when resources (control and support) are optimal for the development of good coping strategies in a highly demanding situation, the employees will need reward for high effort, and hence balance between the components is needed.

Most of the relationships that have been observed in this field would be without significance in society if it were not possible to prove that it is possible to improve health by means of changes in working conditions. Accordingly, the literature on job interventions and their possible effects on health is of considerable importance.

Other Job Stress Related Outcomes

Of particular importance to the link between job stress and cardiovascular disease is the development of atherosclerosis. During recent years it has become increasingly common to measure wall thickness in the carotid arteries – intima media thickness (IMT) – since this reveals early as well as late signs of atherosclerosis. In-depth studies of the early stages of atherosclerosis have shown that psychosocial stress is of significance. Sympathetic arousal increases the likelihood of soft plaques in the arterial wall through a complicated physiological process involving proinflammatory cytokines. Effective activation of the parasympathetic system and rapid slowing of the sympathetic system increases the likelihood that these reactions will be counteracted and the soft plaque will disappear without developing into more severe forms of atherosclerosis (De Couck et al., 2012). In consequence, there are studies which have shown that both the demand–control and effort–reward models are useful in predictions of progression of IMT over time (Eller, 2012).

Another important step in the efforts to explore easily applicable biological stress markers that can be used in practice in the workplace has been the introduction of salivary cortisol measures. There has been great hope that salivary cortisol which mirrors the concentration of free cortisol in plasma would be a very useful indicator. It has been shown that the rise of the salivary cortisol from awakening to half an hour later, is a useful measure of the arousal associated with the day. The findings so far have been mixed (Kristenson et al., 2012) with regard to the usefulness of salivary cortisol variation in general as an index of stress states, with some significant findings for both models in some studies but null findings in several others (Karlson et al., 2012). Paid work is impossible if there is severe HPA regulation disturbance (see above). Most of the work stressors are of a mild nature and large samples are therefore needed for the study of these associations. The interpretations are complicated by the fact that the feeling of being stressed is dampened by a strong cortisol response (Het et al., 2012) and hence simple correlations between self-reported exposure intensity at work and cortisol level cannot be expected. Stressor peaks at work occur unexpectedly and when they occur, the subjects may not report feeling stressed (because of the cortisol peak). In a careful study – with a large number of observations – of the daily stressors for neonatal pediatricians and nurses in critical care, objectively assessed events gave rise to cortisol peaks; but almost three fourths of these peaks were not described as stressful by the subjects themselves (Fischer et al., 2000).

Another outcome that is relevant in linking job stress to illness is heart rate variability (HRV) that is recorded by means of continuous ECG recordings. As long as the subject does not have a large number of cardiac arrhythmias, a high variability in heart rate is an index of good health. Subjects with exhaustion and depression have low total HRV. There are also different components in HRV; ‘high frequency’ variations are reportedly related to the activity in the parasympathetic system whereas the ratio between ‘low frequency’ and ‘high frequency’ variations have been assumed to reflect sympatho-adrenal activity. There are many technical problems in interpreting the recordings and it also makes a difference whether recordings are made on a total day–night variability basis or whether short recordings are made during defined external conditions. Both the demand–control and the effort–reward models have been related to HRV. Thus job strain as well as lack of control (decision latitude) and effort–reward imbalance have been shown in several studies to be related to low total HRV, reduced high frequency power, and high ratio between low and high frequency power (Eller, 2012).

A great emphasis in the present survey has been on cardiovascular disease and related outcomes. The rationale behind this is that cardiovascular disease is an important health outcome that is partly determined by stress-related factors. However, many reports of relevance to job stress deal with emotional outcomes such as depression, depressive feelings, anxiety disorders, and anxious feelings as well as emotional exhaustion and burnout. A recent summary of prospective studies by Bonde (2011) concluded that perception of adverse psychosocial factors (predominantly the demand–control and effort–reward models or their components but also job insecurity and organizational justice) is related to an elevated risk of subsequent depressive symptoms or major depressive episodes.

Environmental and Individual Psychosocial Interventions at Work

Very few studies have actually documented the health consequences of psychosocial job interventions. One early study of cardiovascular risk factors (Orth-Gomer et al., 1994) showed that a program aiming at improved decision latitude and social support for the employees was followed by improved ratio between harmful and protective cholesterol (that is associated with reduced CHD risk) in the experimental but not in the comparison group. The findings could be interpreted to mean that job redesign aiming at improved social relationships and decision latitude could lead to decreased cardiovascular risk. Recently Brisson et al. (2006) have performed controlled evaluations of work organization intervention for health care workers. The intervention program was building upon the demand–control and effort– reward models. It was instituted in close collaboration with the participating worksites and adapted to the specific conditions of each site. Significant effects were reported on mental health outcomes. This group has later developed their intervention program and in new reports significant intervention effects in the form of reduced blood pressure have been reported (Trudel et al., 2011).

Experiences in all EU countries have been summarized (Kompier and Cooper, 1999). Evaluations of systematic efforts to improve working conditions by means of increased decision latitude, support, organizational justice, and reward in order to improve health have typically been more common in the Northern countries.

Recent evaluation studies of the effects of programs for improving managers’ ability to decrease employee stress have been promising (Theorell et al., 2001; Romanowska et al., 2011).

Ongoing Trends

In an increasingly unstable labor market in the future, employment security will become less common and global competition will increase (Aronsson and Goransson, 1999; Johnson, 2008). In most European countries there has been a clear rise in work intensity since the beginning of the 1990s. There have been pronounced changes in the organization of the public sector. In the Nordic countries, for instance, there has also been a decrease in perceived decision authority since the late 1990s particularly among women working in health care and education. Problems with decision authority have arisen during a period when management philosophy has changed in the direction of more financial emphasis. Psychological demands will continue to rise, both because there is more cognitive demand (memorizing numbers, handling computers, etc.) and more emotional demands due to increased customer demands. Numbers of collaborative partners are rising because of the increasing specialization of work, and thus there will be an increasing likelihood of complicated emotional communication for everybody.

Studies in several countries have already shown that workers in temporary employment have a bad position in decision processes. There are indications from several countries that differences in health between favored and less favored workers will increase. The importance of effort–reward balance and organizational justice increases in efforts to decrease job stress.

The basis for social support will change gradually since workers on all levels will rotate more frequently between worksites in different projects than previously. Employers will have a special responsibility for the organization of social support in worksites.

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