People suffering from even low, subclinical levels of psychological stress are at an increased risk of death from external causes and cardiovascular diseases, says a study published today (August 1) in the British Medical Journal (BMJ).
The increased risk of death from both external causes and cardiovascular diseases is 29 per cent each. In both cases, a strong evidence of a dose-response effect was seen, and it remained valid even after taking into account factors such as age, sex, body mass index, systolic blood pressure, physical activity, smoking, drinking and diabetes.
Though stress did cause cancer deaths, only higher levels caused mortality. “Psychological distress in highly symptomatic patients was associated with 41 per cent increased risk of cancer deaths,” the authors say.
Dose-response association
“The main finding of this study was a dose-response association between psychological distress and mortality from cardiovascular disease, and external causes… even in people who would not usually come to the attention of mental health services,” they write. “A similar association with cancer was seen at higher levels of psychological distress.”
Cardiovascular death
Several stresses have been found to cause cardiovascular deaths. For instance, acute stress can alter cardiovascular physiology, which in turn can result in heart attacks even in those not suffering from any cardiovascular disease. Stress and depression could even result in dysregulation of the hypothalamus-pituitary-adrenal axis. Depression alone affects the body in multiple ways.
“Physiological and psychological responses to psychological stressors are designed to protect the organism but that the body’s response can also have harmful effects on health,” notes an accompanying editorial in the same issue of the journal. “It seems reasonable to hypothesise that not ‘coping’ with psychological stressors will lead to symptoms of depression and anxiety.”
While modifying the source of stress is one way of reducing risk, some people might actually go out seeking stressors. “Chang[ing] the psychological interpretation of stressors might reduce their biological impact,” notes the editorial.
The results are based on a meta-analysis of over 68,000 people aged 35 years and above from 10 large prospective cohort studies from 1994 to 2004. Psychological distress was measured using the 12-item General Health Questionnaire (GHQ-12) score and cause of death was extracted from the death certificate.
General Health Questionnaire is a “widely used measure of distress in population studies,” and captures stresses such as anxiety, depression, social dysfunction, and loss of confidence.
