Medically Unexplained Symptoms: Exacerbating Factors in the Doctor-Patient Encounter

This paper proposes that well-intentioned actions by medical practitioners can exacerbate or maintain medically unexplained symptoms (MUS)—i.e. physical symptoms that are disproportionate to identifiable physical disease. The term is now used in preference to ‘somatization’.1 Although research has gone some way to explain the predisposing and precipitating causes of MUS, there is little information on the factors that maintain such symptoms and resulting behaviour. We conducted a search of the Medline and Psychinfo databases using ‘iatrogenesis’ and ‘medically unexplained symptoms’ or ‘somatization’ as keywords; however, the yield of references was disappointing, so we supplemented these with papers that included relevant data even if not explicitly about iatrogenesis. MUS are common. In one study, 30% of new patients attending general medical outpatients had no medical diagnosis to account for their symptoms, whilst a further 22% had a doubtful medical diagnosis.2 Among frequent attenders at secondary care clinics the prevalence of MUS is high,3 and the greater the number of reported symptoms the more disabled the individual is likely to be.4 MUS may or may not be associated with anxiety and depression. Patients with the highest number of MUS are likely to fulfil the psychiatric criteria for somatization disorder—at least 2 years of multiple and various MUS, with persistent refusal to accept advice and reassurance from doctors; functioning impaired. In patients attending general medical clinics the prevalence of either somatization disorder or hypochondriacal disorder is as high as 12%2—in contrast to a community prevalence of 0.1-0.7%.5 The medical specialties employ shorthand descriptions for particular clusters of MUS including irritable bowel syndrome, non-cardiac chest pain, fibromyalgia, chronic fatigue syndrome and repetitive strain injury. They are diagnosed on the basis of symptoms which overlap considerably and have no clear organic aetiology. Factors predisposing to MUS are female gender,6 childhood experience of parental ill-health (particularly paternal),7 childhood abdominal pain8 and lack of care in childhood.9 High rates of ‘life events’ occur in the period predating the onset of MUS in a pattern similar to that seen before the onset of depressive illness.10 In those with somatization disorder there are high rates of personality disorder.11 What are the factors that lead to persistence of MUS in some individuals? Examples of possible precipitating events include chest pain induced by hyperventilation12 and muscle ache after unaccustomed exercise.13 Some of these mechanisms may become chronic. Additional psychosocial factors may be ‘secondary gain’10 (for example, when chronic pain spares a parent the burden of caring for a difficult child) or maladaptive psychological coping strategies.14 In this paper, we focus on the adverse effects of medical interventions at various stages of the doctor-patient encounter.