MRI Shows that Exhaustion Syndrome Due to Chronic Occupational Stress is Associated with Partially Reversible Cerebral Changes.

The present study investigates the cerebral effects of chronic occupational stress and its possible reversibility. Forty-eight patients with occupational exhaustion syndrome (29 women) and 80 controls (47 women) underwent structural magnetic resonance imaging (MRI) and neuropsychological testing. Forty-four participants (25 patients, 19 controls) also completed a second MRI scan after 1-2 years. Only patients received cognitive therapy. The stressed group at intake had reduced thickness in the right prefrontal cortex (PFC) and left superior temporal gyrus (STG), enlarged amygdala volumes, and reduced caudate volumes. Except for the caudate volume, these abnormalities were more pronounced in females. They were all related to perceived stress, which was similar for both genders. Thickness of the PFC also correlated with an impaired ability to down-modulate negative emotions. Thinning of PFC and reduction of caudate volume normalized in the follow-up. The amygdala enlargement and the left STG thinning remained. Longitudinal changes were not detected among controls. Chronic occupational stress was associated with partially reversible structural abnormalities in key regions for stress processing. These changes were dynamically correlated with the degree of perceived stress, highlighting a possible causal link. They seem more pronounced in women, and could be a substrate for an increased cerebral vulnerability to stress-related psychiatric disorders.

Chronic stress is linked to 5-HT(1A) receptor changes and functional disintegration of the limbic networks.

There are increasing reports about stress related cognitive and psychic declines in subjects who have no psychiatric premorbidity, depression, or major life trauma. Yet, little is known about the underlying neurobiology. Based on the typical symptomatology, fMRI data suggesting that stress activates the limbic circuits, and animal data showing a major involvement of the 5-HT(1A) receptor in stress regulation, we hypothesized that enduring daily stress causes widespread limbic dysfunctions, and specific changes of the 5-HT(1A) receptor. To test these hypotheses combined PET studies were carried out in 16 chronically stressed, and 16 non-stressed subjects. Limbic function was tested by measuring cerebral blood flow during rest, and when using an odor activation paradigm. 5-HT(1A) receptor binding potential (BP) was assessed with [(11)C]WAY100635. All subjects went through a battery of neuropsychological tests. Stressed subjects showed a functional disconnection between the amygdala and ACC/medial prefrontal cortex (mPFC), and an impaired odor activation of the ACC. They also displayed a reduced 5-HT(1A) receptor BP in the anterior cingulate (ACC), the insular-cortex, and the hippocampus. Their performance in attention-, odor discrimination-, and semantic memory tasks was impaired, and correlated with the BP-values in the respective region. The degree of reported stress was inversely correlated with activation of ACC, and the 5-HT(1A) receptor BP in the amygdala and hippocampus. Enduring every day psychosocial stress seems to be associated with a limbic reduction of 5-HT(1A) receptor binding and functional disintegration of ACC/mPFC. These changes support the notion of an impaired top-down regulation of stress stimuli, and identify potential targets for early treatment.

Psychosocial and physiological factors in relation to blood pressure at rest--a study of Swedish men in their upper twenties.

The interrelationships between psychosocial factors, several physiological variables and blood pressure (BP) were investigated in 88 young men (aged 26-32 years) in whom high, intermediate or low BP had been recorded at the age of 18 years. In the original high BP group, venous plasma noradrenaline was normal but adrenaline levels elevated. At the follow-up adrenaline correlated with systolic blood pressure (SBP), and this was also so after controlling for overweight and serum gamma-glutamyltranspeptidase [gamma-GT, a marker for alcohol consumption, which showed an independent association with diastolic blood pressure (DBP)]. Low assertiveness (low scores of verbal and indirect aggression) correlated with high BPs, even after controlling for other psychosocial variables. Several associations between psychosocial job variables and physiological variables were found. Among self-reported job variables, excessive 'demands' and 'bossing others' (but not 'decision latitude' or 'psychosocial conflict') were associated with high SBP. Habitual smoking of cigarettes was not associated with BP at rest, but influenced several associations between psychosocial and physiological variables. Men with high BP at rest and low plasma renin activity (PRA) reported more psychosocial problems at work and lower assertiveness than other groups.

Central control of cardiovascular adjustments to exercise.

Voluntary heart rate (HR) control during moderate exercise on a bicycle ergometer was studied in 10 healthy physically conditioned men (5 experimental and 5 control). The results showed that subjects could learn to attenuate the tachycardia of exercise while exercising at a steady work level of 60-70% of maximum HR. Experimental subjects who saw beat-to-beat displays of HR and were instructed to slow HR showed 22% less increase in HR than did control subjects who exercised without HR displays or instruction to slow HR (42.6 vs. 54.6 beats/min). When the control subjects were given feedback in additional sessions, they also decreased HR significantly by 9% (54.6 vs. 49.9 beats/min). Analyses of concomitant respiratory and metabolic data showed that HR attenuation was accompanied by decreased O2 consumption (P less than 0.06) and pulmonary ventilation (P less than 0.01). Rate pressure product also fell, indicating a decrease in myocardial O2 consumption. Comparisons among pre- and postsubmaximal and cardiovascular pulmonary and humoral responses during maximal test sessions suggested that the improvement in cardiopulmonary function during feedback training occurred with no sacrifice to working muscle requirements because blood lactate concentrations were similar. The attenuation of the HR response obtained in the present study indicates that feedback training in physically conditioned subjects can influence cardiovascular responses even under conditions of heavy local demands imposed by working muscles.

The effects of the strain of returning to work on the risk of cardiac death after a first myocardial infarction before the age of 45.

Seventy-nine men who had suffered a myocardial infarction before the age of 45 while they were vocationally active in the greater Stockholm area were followed for five years. Forty-nine survived without cardiac complications and 13 died due to ischaemic heart disease during the period of follow-up. These two contrasting groups were compared with regard to psychosocial risk factors at work before the first myocardial infarction (as reported by the patient when he was interviewed during the weeks after the onset of disease). It was hypothesized that returning to stressful work (high demands and limited possibilities of influencing decisions and developing skills) would be associated with an increased risk of death. All the subjects who died had returned to the work that they had performed prior to the first myocardial infarct. Work performed by these patients was described as having significantly higher psychological demands in relation to the possibility of learning new things and higher demands in relation to variety as well as almost significantly higher demands in relation to influence. Multivariate logistic regression with these factors concerning employment, together with biomedical risk factors recorded at the same time, showed that increasing age, increasing degree of coronary atherosclerosis and number of stenosed coronary arteries, as well as high demands in relation to the possibility of learning new things, were independent predictors of death due to coronary arterial disease. The remaining 17 subjects either survived a re-infarction, or had coronary arterial by-pass surgery during the period of follow-up. This heterogeneous group occupied intermediate positions with regard to psychosocial job factors.

Psychosocial work conditions before myocardial infarction in young men.

All male patients in the greater Stockholm area who had survived a myocardial infarction below the age of 45 were examined with regard to medical and psychosocial risk factors 3-6 months after the onset of the infarction. For each patient, a male control subject was randomly selected after matching with regard to age and residence area. In the patient group, coronary angiograms were performed and rated with regard to degree of coronary atherosclerosis. The psychosocial variables were not correlated with degree of coronary atherosclerosis. Excessive work demands combined with boredom at work ("variety" and "intellectual discretion") were significantly more often reported by the patients after adjustment had been made for life style factors. In the multivariate analysis a high LDL/HDL cholesterol ratio, a high cumulative tobacco consumption, high demands in relation to variety at work as well as high demands in relation to influence over work and finally a low alcohol consumption were significant independent predictors of case status. Excessive work demands in themselves did not differentiate cases from controls.

Type A behaviour, education and psychosocial work characteristics in relation to ischemic heart disease--a case control study of young survivors of myocardial infarction.

The interaction of Type A behaviour, psychosocial work environment and education in relation to medical risk factors for IHD was analyzed in a case-control study of male and female post-MI-patients under age 45. In multivariate analysis LDL/HDL-cholesterol ratio and smoking (explaining 27 and 6% of the variance) emerged as the two most important discriminators of patients from control subjects. The third factor, variety of work tasks, explained 5% of the variance. Type A behaviour ranked as factor no. 7, explaining only 2% of the variance and educational level did not reach statistical significance as an independent explanatory factor. When the sample was divided into men and women with high and low education, most of the patient-control difference in Type A and psychosocial work characteristics was found among highly educated men on one hand and women with a low level of education on the other. Thus Type A behaviour seems to be less important and psychosocial work environment more important in adding psychosocial risk to the medically established risk of IHD.

Job strain and ambulatory blood pressure profiles.

Occupational characteristics were used to study the role of job stress in the pathogenesis of hypertension. Ambulatory 24-h recordings of blood pressure were made for 161 men with borderline hypertension. From the occupational classification system scores for psychological demands, control, support, physical demands, and occupational hazards were obtained. The results indicated that the ratio between psychological demands and control (strain) was significantly associated with diastolic (but not systolic) blood pressure at night and during work. The association between job strain and diastolic blood pressure at night and during work was greatly strengthened when the subjects with occupations classified as physically demanding were excluded from the analysis. The conclusion was reached that a measure of job strain derived from the occupational classification is useful in predicting variations in diastolic blood pressure levels during sleep and work for men with borderline hypertension.

Changes in job strain in relation to changes in physiological state. A longitudinal study.

A sample of 73 men and women aged 22-63 years and working in six different occupations (air traffic controllers, waiters, physicians, symphony orchestra musicians, baggage handlers, and airplane mechanics) participated in a longitudinal study four times during a year. The spontaneous variations in job strain (determined as the self-reported ratio between psychological demands and decision latitude) were substantial. The average difference between the occasion with the highest level of strain and the occasion with the lowest level was 25% of the total mean. Systolic blood pressure during workhours, as well as self-reported sleep disturbance, increased when demands increased in relation to decision latitude. Among men with a depressive tendency (according to a diary) morning plasma prolactin levels increased markedly with increasing job strain. Among subjects with a positive family history of hypertension the increase in systolic blood pressure at work was particularly pronounced, and among the men in this group a lower than expected level of morning cortisol was found measured during the period with the highest level of strain.

On the interplay between socioeconomic factors, personality and work environment in the pathogenesis of cardiovascular disease.

This article summarizes some of the major findings in research on associations between psychosocial factors and cardiovascular illness. Methodological difficulties are discussed. Findings from some of the authors' own studies serve as illustrations. It is emphasized that an interplay between environmental and individual factors is of great importance. Personality factors relevant to the risk of cardiovascular illness may distort individual descriptions of the work environment. Cardiovascular risk factors such as cigarette smoking and repeated blood pressure elevations may be influenced by psychosocial factors. Lack of intellectual discretion at work, particularly if combined with excessive demands, may increase the risk of cardiovascular illness.

Associations between financial strain and the diurnal salivary cortisol secretion of long-term unemployed individuals.

OBJECTIVE: The study investigated the associations between self-rated financial strain and overall diurnal salivary cortisol levels, as well as secretory patterns among long-term unemployed individuals. METHODS: Psychosocial and life-style variables were assessed by means of questionnaires among 85 participants (mean age 42+/-9 years; 56% females). Salivary cortisol was sampled on four occasions during a 24-hour period and data was analysed separately for men and women. RESULTS: Among females, high financial strain was related to higher overall cortisol levels, and to elevated levels in the evening. These associations did not reach significance among men. Multivariate analyses showed that evening levels of cortisol were positively associated with financial strain, but largely unrelated to life-style variables and psychological distress. CONCLUSIONS: The results suggest that high financial strain influences the diurnal cortisol secretion of unemployed individuals in terms of elevated cortisol levels in the evening. The mediating mechanisms are in need of further investigation.