HYPOCHONDRIASIS 47

preoccupation with health. As described above, the assumptions which characterise many of these patients can result in the addition of a confirmatory bias which interacts with all three of the factors described here, further fuelling the misinterpretation of bodily symptoms and bodily state.

Increased physiological arousal

Increased physiological arousal (which stems from the perception of threat) leads to increased occurrence of autonomically mediated sensations; these sensations are often interpreted by the patient as further evidence that they are ill. For example, if a patient notices an increase in sweating and has the thought that this is a sign of a serious hormonal imbalance, sweating will increase when this thought occurs, appearing to provide further evidence of ‘disturbance’.

Focus of attention

Normal variations in bodily function (including those which give rise to bodily sensations) or previously unnoticed aspects of appearance or bodily function may be noticed more readily than had previously been the case. The patient is then likely to conclude that these perceived changes represent pathological changes from ‘normal function’ when this is not actually so. For example, a patient noticed that the roots of his fingernails looked pale and he had white spots on his nails, and interpreted this as a sign of a ‘hormone problem’. He found this observation extremely upsetting, and could not believe that he could have missed something so distressing in the past, strongly supporting his view that this must represent a new phenomenon. Focus of attention may also lead to actual change in physiological systems where both reflex and voluntary control are involved (breathing, swallowing, muscular activity, and so on). For example, patients may notice difficulty in swallowing dry foods which they interpret as a possible sign of throat cancer. Focusing on swallowing can lead to undue effort and increased discomfort and difficulty.

Avoidant behaviours

Disease conviction and illness phobia can both be conceptualised from a behavioural perspective. In both instances, anxiety has become conditioned to stimuli associated with illness; for the illness phobic, these stimuli are most often external (hospitals, doctors, medical information, other people being ill, and so on) For hypochondriacal patients the stimuli are predominantly internal (bodily sensations such as stomach discomfort, bodily signs such as lumps under the skin), although the hypochondriacal patient’s attention is often brought to the bodily variation by external factors such as reading about a particular disease. The illness phobic copes with the anxiety by avoidance of the stimuli concerned. However, because of the nature of the stimuli involved, the hypochondriacal patient seldom has this option, so resorts instead to behaviours designed to neutralise the anxiety, like the behaviour more typical of obsessional patients. In both instances, avoidant behaviours are prominent and serve to terminate exposure to the feared stimuli, thereby preventing habituation from taking place and perpetuating the condition.

The cognitive-behavioural hypothesis we have formulated gives avoidant behaviours even broader functional properties than a purely behavioural view. Avoidant behaviours are crucial in three respects. First, they prevent the patient from learning that the things which they fear do not actually happen. That is, the things which the patient fears are accompanied by negative thoughts; in normal circumstances, the reality of these thoughts about negative outcomes would become clear in the course of time. However, avoidance prevents this reappraisal of threat. Second, avoidance functions to keep the patient’s attention focused on the negative thoughts, resulting in a characteristic preoccupation. Third, in some patients the checking behaviours have a direct impact on the bodily variations which elicited the thoughts in the first instance. For example, a patient noticed a mild pain in one of his testicles. He had the thought that this may have been caused by cancer. Over the next few days he repeatedly probed his testicle, which became more painful and inflamed, which he believed confirmed his self-diagnosis. When he stopped checking, the symptoms (including pain) resolved within three days.

The importance of reassurance

The significance of reassurance seeking as a type of avoidant behaviour is often neglected in hypochondriacal patients, despite it being so prominent that it is part of the definition of the disorder. Reassurance seeking and provision may be of fundamental importance in the maintenance of the condition. According to the DSM III-R criteria, a patient cannot be diagnosed as hypochondriacal until they have had some unsuccessful medical reassurance. Hypochondriasis can be seen to be unusual in that the diagnosis depends not only on the characteristics of the patient but also on the actions of doctors. The