Fibromyalgia and the concept of resilience.

The concept of resilience varies according to the context in which it is used. Resilience is broadly defined as a protective factor that makes people less vulnerable to future adverse life events, in this implying the previous occurrence of an adverse event that has to be confronted before individual equilibrium can be restored. This definition can be applied to fibromyalgia and other chronic pain situations. Resilience is profoundly related to reaction to acute or chronic stress, and is therefore involved in the stress response system. Corticotropin-releasing factor can be considered a fundamental biological element of resilience, which also involves neural mechanisms such as the hypothalamic-pituitary-adrenal (HPA) axis, the locus coeruleus/norepinephrine system, the mesolimbic reward circuit and the fear circuit. Resilience also has a genetic basis: certain genetic characteristics, affect the degree of vulnerability to chronic stress. The number of psychiatric symptoms in healthy adults with high resilience scores do not change when they are exposed to stressing life events, whereas less resilient people develop additional symptoms. This is a typical clinical feature of fibromyalgia. Although resilience could be a therapeutic target for any chronic pain condition, it is an under-developed area of research, particularly in the light of the emerging interactions of positive emotions, physical health, and changes in pro-inflammatory cytokine levels. Given the lack of any pharmacological treatment capable of controlling more than 30-50% of the cases of chronic pain, there is a need to discover new therapeutic targets and strategies capable of changing a non-resilient phenotype into a more resilient phenotype, especially in the case of chronic pain conditions that cannot be explained by a lesion or a disease affecting the somatosensory system. This holds true of fibromyalgia, which is characterised by a complex combination of positive signs and symptoms that vary enormously from person to person depending on a wide range of pathophysiological changes in which genotype and, more importantly, environmental factors may play a major role in developing a more or less resilient personality.