Читать книгу The Sickening Mind: Brain, Behaviour, Immunity and Disease - Paul Martin - Страница 13

Sometimes – quite often, in fact – people drop dead with little or no warning because something goes wrong with their heart. This phenomenon is called sudden cardiac death. It is normally defined as an unexpected heart failure within twenty-four hours of the first symptoms (if any) being noticed.

Sudden cardiac death accounts for about 15 per cent of all mortality from natural causes. Though victims may have no previous medical history of heart problems, autopsy generally reveals a pre-existing but hitherto undiscovered disease. Unfortunately, in more than half of all cases the first manifestation of this disease is death.

For centuries people have believed that severe psychological stress, grief, fear, anger or other strong emotions can trigger sudden cardiac death. There is massive anecdotal evidence that distressing events such as the death of a loved one, the loss of a job or even a heated argument can trigger a fatal heart attack. In recent years scientists have accrued a satisfyingly solid mountain of systematic evidence to confirm the anecdotes.

When scientists analyse the immediate precursors of sudden cardiac death they consistently find that a large proportion of its victims have experienced unusually high levels of emotional distress in the hours or days leading up to death. One study, for example, found that 40 per cent of men who died unexpectedly from heart failure had experienced a significant emotional upset, such as being involved in a car accident or receiving notification of divorce proceedings, within the twenty-four hours immediately preceding their death. There have even been documented medical reports of individuals dying after being severely disturbed by upsetting thoughts or recollections of a traumatic experience.

One of the most common precursors of sudden cardiac death is the extreme fatigue and exhaustion known as burnout. Like consumption in the nineteenth century, burnout has become something of a bizarre status symbol. Burnout is seen as the ‘red badge of courage’ in professional circles, proof of Herculean labours and overwhelming workloads. (This says a great deal about present cultural values. In the nineteenth century consumption lent status because it supposedly denoted creativity and artistic passion; nowadays it is the sloggers we prize.)

Whatever the cultural overtones, there is a significantly higher risk of sudden cardiac death for victims of burnout. Those who exhibit the classic symptoms of intrusive anxiety, irritability and mental exhaustion may feel that way because of a mechanical fault in their heart. In many cases, however, burnout is more a symptom of prolonged psychological stress. In combination with a pre-existing weakness in the heart or coronary arteries it can easily be lethal. Dutch research which tracked the health of a large sample of middle-aged men over several years found that individuals who reported feeling mentally and physically exhausted at the end of the day were more than twice as likely to die from a heart attack. This was true even for men who had hitherto been free from any coronary heart disease.

In chapter 8 we shall be looking in greater depth at the biological mechanisms whereby the mind can damage the heart and coronary arteries. Suffice it here to say that there are plenty of well-understood biological mechanisms which enable stress-induced changes in the brain to trigger sudden cardiac death, especially where coronary heart disease is already present.

Sudden death can also be provoked by traumatic events on an impersonal scale. We have already considered the case of the Israeli citizens who died during the Gulf War from psychological stress generated by Iraqi missile attacks. Nature has conducted some of its own experiments in stress-induced death. Take earthquakes, for example. An analysis of mortality statistics immediately after a major earthquake will usually reveal a transient rise in the number of deaths from heart failure and other natural causes, unconnected with the direct physical effects of the earthquake. For instance, in 1978 the Greek city of Thessaloniki was hit by two earthquakes. Official records showed a marked increase in deaths from natural causes, especially heart failure. During the three-day period spanning the earthquakes and their immediate aftermath, the rate at which the local population were dying from heart disease shot up by 200 per cent and the death rate from other natural causes increased by 60 per cent.

Similarly, when Australian scientists investigated the aftermath of an earthquake which struck New South Wales in 1989 they found that the incidence of fatal heart attacks in the locality went up by 70 per cent. In these and other cases it was clear that psychological stress had brought about the premature deaths of vulnerable individuals.

Then we have those strange tales of voodoo, or ‘hex’, death. The unfortunate victim is ritually cursed by a witch doctor, voodoo priest, bokor or other symbolic authority figure. Once the death sentence has been pronounced the victim duly obliges by giving up the ghost and dying, usually within a few days. Competent and trustworthy authorities have been documenting instances of voodoo death since at least the sixteenth century, in places as far apart as Africa, South America, the Caribbean and Australia. It cannot be dismissed as the product of lurid fantasies.

The religious and cultural details vary, but reliable reports of voodoo death share certain basic features. First and foremost, the victim must be highly suggestible, with an unquestioning belief in the power of the sorcerer or witch doctor who curses him. He must also be totally convinced that he is powerless to do anything to save himself. An attitude of helplessness is essential: once the bone has been pointed or the curse uttered, the victim loses any will to live. Sceptics, scientists and tourists do not die from voodoo curses. A third important ingredient is social pressure. It speeds things along no end if everyone else in the victim’s social world shares the same beliefs. Family and friends reinforce the victim’s belief in the inevitability of death, abandoning the unfortunate individual to die in complete isolation.¹ The enormous importance of social relationships for mental and physical health is a theme we shall return to later.

Literature is replete with characters who drop dead from the effects of overpowering emotion. Shakespeare’s King Lear, for example, dies of a broken heart when his favourite daughter Cordelia is cruelly murdered shortly after Lear is reconciled with her. On discovering Cordelia’s body, Lear gives vent to his crushing grief:

Howl, howl, howl, howl! O, you are men of stones!

Had I your tongues and eyes, I’d use them so

That heaven’s vault should crack. She’s gone for ever.

Then Lear drops down dead.