Work stress as a risk factor for major depressive episode(s)

ABSTRACT

Background. Major depression is a prevalent mental disorder in the general population, with a multi-factorial etiology. However, work stress as a risk factor for major depression has not been well studied.

Method. Using a longitudinal study design, this analysis investigated the association between the levels of work stress and major depressive episode(s) in the Canadian working population, aged 18 to 64 years. Data from the longitudinal cohort of the Canadian National Population Health Survey (NPHS) were used (n=6663). The NPHS participants who did not have major depressive episodes (MDE) at baseline (1994-1995 NPHS) were classified into four groups by the quartile values of the baseline work stress scores. The proportion of MDE of each group was calculated using the 1996-1997 NPHS data.

Results. The first three quartile groups had a similar risk of MDE. Those who had a work stress score above the 75th percentile had an elevated risk of MDE (7.1%). Using the 75th percentile as a cut-off, work stress was significantly associated with the risk ofMDE in multivariate analysis (odds ratio=2.35, 95% confidence interval 1.54-3.77). Other factors associated with MDE in multivariate analysis included educational level, number of chronic medical illnesses and child and adulthood traumatic events. There was no evidence of effect modification between work stress and selected sociodemographic, clinical and psychosocial variables.

Conclusions. Work stress is an independent risk factor for the development of MDE in the working population. Strategies to improve working environment are needed to keep workers mentally healthy and productive.

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(Taken from: Wang, J. (2005). Work stress as a risk factor for major depressive episodes. Psychological Medicine, 35 , 865-871)

On-the-job stress bad for the heart

A recent British study has strengthened the link between on-the-job stress and the risk of heart disease, stroke and other cardiovascular problems. According to the report, people who described their job as stressful are more likely to develop metabolic syndromes: a collection of cardiovascular risk factors such as obesity, high blood pressure and high cholesterol levels. Furthermore, the number of employees reporting psychiatric disabilities is steadily growing, increasing employee absenteeism and costing companies in lost productivity and revenue. However, companies also need to consider the costs of reduced productivity due to health problems being exposed to the employee at work.

Previous reports have also shown a link between work stress and heart disease, but "the biological processes underlying this association remained unclear," says Tarani Chandola , a senior lecturer in epidemiology and public health at University College London, and lead author of the new research. "The study shows that there is a dose-response association between exposure to work stress and the metabolic syndrome." The findings appear in the Jan. 21 issue of the British Medical Journal. Chandola and his colleagues questioned more than 10,000 British civil servants between the ages of 35 and 55 over a 14-year period, asking them four times during that period to say whether they felt stress on the job. Measurements of blood pressure, cholesterol and other metabolic syndrome components also were taken.

"There was a stepwise increase in the odds of the metabolic syndrome with increasing levels of exposure to work stress," Chandola says. Men with chronic work stress were twice as likely to develop metabolic syndrome than those reporting no work stress. Women with work stress were also more likely to develop the syndrome, but there were only a few of them in the study.

Why should stress lead to metabolic syndrome, which has also been linked to type 2 diabetes? Chandola offers some thoughts. Stress might affect the autonomic nervous system, which controls the activity of organs, blood vessels and glands, he says. Alternatively, stress might influence the production of hormones throughout the body. "We are currently investigating the effect of work stress on both systems," he says. Steps need to be taken to help relieve stress, Chandola says. Previous reports found that civil servants who felt they were being treated fairly at work had a reduced risk of heart disease, while the risk was higher for those who felt they had little or no control over their work.

"Studies on workplace redesign to increase a worker's sense of control and participation at work have resulted in fewer sick days amongst workers in the experimental group," Chandola says. On the individual level, he says, counselling to modify a worker's sense of control might be helpful.

(Based on articles from Monitor on Psychology, January 2006, volume 37)