The potential role of illness expectations in the progression of medical diseases

The potential role of illness expectations in the progression of medical diseases. Francesco Pagnini. BMC Psychology, volume 7, Article number: 70 (2019). Nov 8 2019. https://bmcpsychology.biomedcentral.com/articles/10.1186/s40359-019-0346-4

Abstract
To what extent can one’s mind promote direct changes to the body? Can one’s beliefs about the body become a physical reality, without mediating effects from behaviors? Specifically, can medical symptoms and the course of a disease be directly affected by a person’s mindset about the illness?
There is a vast literature about placebo and nocebo effects, that promote physical changes by creating the expectation of a change through a primer (for example, a fake pill). Placebos, however, often imply deception, or at least ambiguity, to be effective. The concept of Illness Expectation describes the expectations, both implicit and explicit, that a person who has received a diagnosis makes about the course of the disease. It can be characterized by different degrees of rigidity, and it is argued here that these expectations can ultimately lead to changes in the disease progression. These changes may happen through behavior modifications, or through a non-behavioral pathway, which may deserve exploration efforts from the scientific literature.

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Effects of expectations on the body

One of the main operational mechanisms of placebos is represented by cognitive expectations, which in turn are expected to promote the occurrence of physiological changes in the body [11]. In general, placebo and nocebo effects have been studied with a primer, such as a sugar pill, that influences or conditions the person to anticipate an effect. The expectation of a medical effect promotes both subjective and objective (physiologic) changes, with clinical improvements or worsening [12]. However, expectations are not only prompted by drugs or interventions. In fact, every individual with a medical condition develops a certain mindset toward the illness [13], with expectations that spontaneously emerge. These expectations, which represent the result of the elaboration process of the information collected about the disease [14], can promote different physiological effects [15]. For example, blood glucose levels in people with type II diabetes are influence by perceived time and expected values, rather than being a mere physiological process [16]. Furthermore, expectations can influence the ageing process: older adults who think about ageing as associated with negative characteristics tend to experience a greater loss of physical function and a reduced survival, compared to those who held positive expectations [17].

Illness perceptions and health beliefs

Expectations about the disease are a central component of illness perceptions and health beliefs, which are well-established concepts in health psychology [18]. Illness Perception is often explored within the theoretical framework of the Common Sense Model (CSM) of Illness Representation [19]. In the CSM theory, patient’s illness perceptions include beliefs about what precipitated the illness (causes), how long it will last (timeline), the impact on the patient’s life (consequences), which symptoms are attributed to the illness (identity), and how the condition can be controlled or cured by the patient’s behavior (personal control) or by the treatment (treatment control). In the CSM, expectations are considered as an underlying component of the different beliefs [20, 21]. Emotional components are another key aspect of the CSM, which may interfere with cognitive processing, and it could be a source of confusion during the assessment process. For example, one of the most utilized instruments for the assessment of illness perception, the Brief Illness Perception Questionnaire [22] includes items like “How much does your illness affect you emotionally?”, which are somehow related to the expectations, but refer directly to the emotional domain. The same concern deals with questions about consequences in everyday life (e.g., “My illness has serious economic and financial consequences”, from the Illness Perception Questionnaire Revised [23]).

Thus far, most published research referencing the Illness Perception construct focuses on the role of disease representations in explaining both coping and outcomes in patients with a wide range of health conditions [24, 25]. Specifically, health psychologists have explored how disease representations can lead to lifestyle modifications, eventually leading to changes in the medical outcomes [26]. For example, adherence to the medical treatment, or lifestyle choices like eating, exercising, or smoking, can be influenced by illness representations. A person who perceives that nothing can change the course of the disease, for example, may be more prone to avoid exercising or taking prescribed medicine [27]. In other words, the effects of Illness Perceptions on the body (namely, on the course of the disease or its symptoms) have been mainly explored as mediated by behavior changes [28]. The main difference between the construct of Illness Perception and Illness Expectation is their specificity: while the former is a multifaceted concept that includes several aspects of the illness experience, the latter is a specific element, the anticipation of the future illness-related scenarios, which is merely cognitive.

Emotions and somatic changes

[...] Briefly, we know that negative emotions (e.g., depression, stress) have, among other effects, a strong impact on human physiology [29], often reflecting on poorer medical outcomes, in the case of chronic diseases. For example, depressive states and stress have been associated with reduced survival rate in patients with cancer [30]. The mechanisms underlying these associations are still under investigation.

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