Research keeps accumulating that confirms the damaging impact of stress — all kinds — upon our mind/body/spirit. This analysis of several studies, reported in the British Medical Journal, sound that stress is linked with increased risk of death, from all sources. I think the larger issue that this highlights, indirectly, is that we are socially conditioned to adapt to values and behavior and a number of norms that, themselves, are unhealthy. That, in turn, generates a wide range of emotional and physical consequences. The report was summarized in MedPage today:
Even at low levels, psychological distress was significantly associated with an increased risk of mortality from several causes, researchers found.
A meta-analysis of 10 British cohort studies showed that the risk of all-cause mortality in adults with the lowest level of psychological distress — termed subclinically symptomatic — was significantly higher than that of asymptomatic adults at an age- and sex-adjusted hazard ratio of 1.20 (95% CI 1.13 to 1.27), Tom Russ, MRCPsych, of the National Health Service Scotland, and colleagues wrote online in BMJ.
The study measured the association of psychological distress with death by any cause, cardiovascular death, cancer death, and deaths from external causes using data from the Health Survey for England. The survey included data from 1994 to 2004 on 68,222 adults ages 35 or older, mean age 60 years, who were free of cardiovascular disease and cancer, and who lived in a private household in England at baseline.
Participants had measures of psychological distress taken at a household visit using a 12-item version of the General Health Questionnaire (GHQ-12) — a unidimensional scale of psychological distress that includes symptom measures for anxiety, depression, social dysfunction, and loss of confidence.
Those surveyed were grouped into one of four categories based on their score: asymptomatic, subclinically symptomatic, symptomatic, and highly symptomatic.
Results were adjusted for age, sex, social class, body mass index, systolic blood pressure, physical activity, smoking status, alcohol consumption, and diabetes at baseline. The participants were followed for a mean 8.2 years.
“All participants with any psychological distress, even those with low GHQ-12 scores (and therefore considered subclinically symptomatic), were at an increased risk of mortality from all causes, cardiovascular disease, and external causes,” Russ and co-authors wrote.
This association was significantly predictive at all symptomatic levels when adjusted for all covariates, except at the lowest levels of external-cause deaths, which had a positive trend for the association. By cause of death, fully adjusted hazard ratios for patients labeled subclinically symptomatic and for those with one standard deviation disadvantage in the GHQ-12 scores included:
- All causes: subclinically 1.16 (95% CI 1.13 to 1.27), one deviation 1.16 (95% CI 1.12 to 1.20,P<0.001)
- Cardiovascular disease: subclinically 1.25 (95% CI 1.08 to 1.44, P<0.001), one deviation 1.17 (95% CI 1.12 to 1.22, P<0.001)
- External cause: subclinically 1.23 (95% CI 0.90 to 1.70, P=0.001), one deviation 1.32 (95% CI 1.13 to 1.55, P=0.001)
Although low and average levels of psychological distress were not predictive of cancer deaths, there was a significant association in highly symptomatic adults at an age- and sex-adjusted hazard ratio of 1.09 (95% CI 1.04 to 1.13, P<0.001), but this trend lost significance when adjusted individually and fully for all covariates.
The authors noted that the association of all-cause and cardiovascular mortalities and the trend for deaths by external causes with subclinical levels of psychological distress was of particular importance because those lower levels of distress “would not usually come to the attention of mental health services.”
“Further research is required to investigate whether treating psychological distress, including overt depression or different aspects of distress, could have an ameliorating effect on the increased mortality demonstrated here,” Russ and colleagues concluded.
Several mechanisms may directly tie psychological distress to cardiovascular and other potentially fatal events, said Glyn Lewis, PhD, of the University of Bristol in England, in an accompanying editorial.
He hypothesized that cardiovascular deaths could be tied to stress response involving the hypothalamus-pituitary-adrenal axis and the autonomic system and that changes in inflammatory cytokines could also cause cardiovascular stress.
Lewis noted that cognitive behavioral therapy could help modify patients’ interpretation of stressors even in those not meeting diagnostic levels of psychological distress, but that “there is currently no evidence that these methods can be disseminated to the population at large to help people reduce perceived stress.”
Russ and co-authors noted a number of limitations with their study, including a lack of clinical diagnosis from the GHQ-12, a large number of data missing from participants, and potential confounding from hidden somatic illness.