Taken at face value, the term ‘psychosomatic’ simply means the interaction of psyche (mind) and soma (body). As such it is a non-controversial concept that points out the many ways in which psychological factors affect the expression of physical disorder and vice-versa. Few doubt that stress makes many physical illnesses worse, at least as far as symptoms are concerned. There are not many physical illnesses in which the outcome is unaffected by psychological factors: depression after a heart attack, for example, has a worse effect on prognosis than smoking.

However, calling a condition psychosomatic implies something more – the primacy of the psyche over the soma. Going back to the influential theories and practice of PSYCHOANALYSIS, many diseases have been proposed as the result of psychological factors; these have included PEPTIC ULCER, ULCERATIVE COLITIS, ASTHMA, PSORIASIS and others. In this view, much physical disorder is due to repressed or excessive emotions. Likewise it is also argued that whereas some people express psychological distress via psychological symptoms (such as anxiety, depression and so on), others develop physical symptoms instead – and that they are also at greater risk of physical disease.

The trouble with this view is that medical advances repeatedly show that it goes too far. Stress certainly causes physical symptoms – for example, DYSPEPSIA – but the belief that it caused peptic ulcers vanished with the discovery of the true cause: colonisation of the stomach by the bacterium, Helicobacter pylori. Of course, stress and social adversity affect the risk of many diseases. For example, the incidence of heart disease among UK government employees (civil servants) has been shown to be influenced by their social class and their degree of job satisfaction. But we do not know how this works. Some argue that social adversity and stress influence how the heart functions (‘He died of a broken heart’). Stress can also affect tests looking at IMMUNITY, but it cannot cause AIDS/HIV, and we do not know if there is a link running from stress to abnormal immune function to actual illness.

We can say that psychological factors provoke physical symptoms, and often even explain how this can happen. For example, when you are anxious you produce more epinephrine (adrenaline), which gives rise to chest pain, ‘butterflies in the stomach’ and PALPITATION. These symptoms are not ‘all in the mind’, even if the trigger is a psychological one. People who are depressed are more likely to experience nearly every physical symptom there is, but especially pain and fatigue. Taken as a whole, psychologically induced symptoms are an enormous burden on the NHS and probably responsible for more doctor visits and sickness absence than any other single cause. Also we can be confident that social adversity and stress powerfully influence the outcome of many illnesses; likewise, a vast range of unhealthy activities and behaviours such as smoking, excessive alcohol intake, excessive eating, and so on. But we must be careful not to assume that our emotions directly cause our illnesses.