Stress can truly kill

Emotional distress, also known as psychological distress, can increase the risk of death in the general population. Anecdotal evidence has shown that distress leads to a myriad of health disorders. [Psychol Med 1995;25(5):1073-86, Ann Epidemiol 2004;14:467-72]

Emotional distress, a term referring to the signs and symptoms of depression and anxiety, has been linked to an increased risk of premature mortality, cardiovascular disease, susceptibility to infection and, potentially, all cancers. [Psychol Med 1995;25(5):1073-86, Ann Epidemiol 2004;14:467-72]

Signs and symptoms of depression can include fatigue and lack of energy; and feelings of hopelessness, helplessness and worthlessness. Signs of anxiety include the feeling of ‘butterflies’ in the stomach, pounding heart, startling easily, muscle tension, and overwhelming feelings of panic and fear.

Bridging emotion and disease

The link between emotions and disease was recognized for as long as human beings roamed the earth. The recognition that emotions affect blood pressure, for example, dates as far back as the early 1900s. Research into human behavior has postulated relationships between anger regulation and blood pressure, and this has been echoed in animal models that have shown the relationship between brain involvement and fluctuating blood pressure.

Recent animal investigations have reinforced this relationship and further implicated immune influences on blood pressure control. The advent of brain imaging has been useful in defining more clearly the neural involvement in hypertension, and providing a possible bridge between behavioral and self-reported information in human and animal models.

Genetic studies, too, have shown that psychological distress can cause the premature shortening of telomeres, which is an indication of accelerated aging. Telomere length is slowly being accepted as an important biomarker of biological aging. [Psychol Med 2012:1-9 Epub ahead of print, Psychosom Med 2011;73(7):541-7]

Telomeres are a region of repetitive nucleotide sequences at each end of a chromosome which protect the end of the chromosome from deterioration or from fusion with neighboring chromosomes. In effect, the more the telomeres are degraded, the more susceptible the chromosome is to damage and mutation.

In 2009, the Nobel Prize in Physiology or Medicine was awarded jointly to Elizabeth Blackburn, Carol Greider and Jack Szostak for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase. With this discovery, the doors for research in telomeres were swung open and the effects exerted by telomeres were slowly unveiled.

Current evidence

A recent study published in the British Medical Journal has established that any level of psychological distress is associated with increased mortality and an increased risk of death from cardiovascular disease, external causes and even cancer (at higher levels of distress). [BMJ 2012;345:e4933 doi: 10.1136/bmj.e4933]

The study, partially funded by the Wellcome Trust, involved researchers from University College London and the University of Edinburgh. They analyzed data of over 68,000 adults aged 35 years and over who took part in the Health Survey for England between 1994 and 2004.

The aim was to measure the role of psychological distress as a risk factor for death from all causes, cardiovascular disease, cancer and external factors occurring over an 8-year period.

Psychological distress was measured using a recognized scale ranging from no symptoms to severe symptoms of stress and anxiety. Death certificates were used to determine cause of death.

“We found that psychological distress was a risk factor for death from all causes, cardiovascular disease and external causes – the greater the distress, the higher the risk. However, even people with low distress scores were at an increased risk of death.

“Currently, these people are unlikely to come to the attention of mental health services due to these symptoms and may not be receiving treatment,” said lead author Dr. Tom Russ, a clinical research fellow at Alzheimer Scotland.

“These associations also remained after taking into account other factors such as weight, exercise, smoking, alcohol consumption and diabetes. Therefore, this increased mortality is not simply the result of people with higher levels of psychological distress smoking or drinking more, or taking less exercise,” said Dr. David Batty, the senior author and Wellcome Trust fellow, department of epidemiology and public health, University College London.

The study is the largest so far to show a dose-response relation between psychological distress and mortality, and has potentially important implications for treatment, the authors said. An accompanying editorial commented that the findings added to evidence that suggest a causal association between psychological distress and cardiovascular disease, but it remains unclear how physicians should intervene.

“The fact that an increased risk of mortality was evident, even at low levels of psychological distress, should prompt research into whether treatment of these very common, minor symptoms can modify this increased risk of death,” Russ said.

Expert reactions

“People with mental health problems are among the most vulnerable in society. This study highlights the need to ensure they have access to appropriate healthcare and advice so that they can take steps to improve the outcome of their illness,” said Dr. John Williams, head of neuroscience and mental health at the Wellcome Trust.

“These findings are important and timely, particularly following recent cuts that are affecting mental health services in the UK. The study clearly shows a link between psychological distress in the form of anxiety and depression and increased risk of death,” said Dr. Jennifer Wild, a consultant clinical psychologist at the Institute of Psychiatry, King’s College London.

“It should also be noted that distress could be unaccounted for contributors to mortality, such as particular bacteria or viruses, which are not easily or routinely measured. On the whole, however, the findings underscore the link between physical and mental health and the need to alleviate even minor symptoms of anxiety and depression since this may improve longevity.

People should not ignore their mental health or go for ‘quick fixes’ in the form of medication, which GPs typically choose. Treatments that have a strong evidence base, such as CBT [cognitive behavioral therapy], and lead to higher rates of long-term recovery may be particularly important for helping people to overcome anxiety and depression and enjoy better overall health,” Wild added.

Author: Leonard Yap

References:

BMJ 2012;345:e4933 doi: 10.1136/bmj.e4933
Psychol Med 2012:1-9 Epub ahead of print.
Ann Epidemiol 2004;14:467-72.
Lancet 2007;370(9592):1089-100.
J Am Coll Cardiol 2008;52(25):2156-62.
Psychosom Med 2011;73(7):541-7.
JAMA 2008;300(20):2379-88.
BMC Med 2009;7:79.
Psychol Bull 2004;130(4):601-30.
Stroke 2002;33:5-6.

Culture and Depression: Studies in the Anthropology and Cross-Cultural Psychiatry of Affect and Disorder, Comparative Studies of Health Systems and Medical Care, Volume 16 of Culture and Depression Series University of California Press, Berkeley and Los Angeles, California, 1986.

The Nobel Prize in Physiology or Medicine 2009, www.nobelprize.org/nobel_prizes/medicine/laureates/2009/Accessed on 29 August