Background: Fibromyalgia is characterized by an amplified pain response to various physical stimuli. Through biological and behavioural mechanisms, patients with fibromyalgia may also show an increase of pain in response to emotions. Anger, and how it is regulated, may be particularly important in chronic pain.
Aim: To examine, among patients with fibromyalgia, whether anger during everyday life amplifies pain and whether general and situational anger inhibition and anger expression modulate the anger–pain link.
Methods: For 28 consecutive days, 333 women with fibromyalgia (mean age 47 ± 12 years) reported their transient anger and state anger inhibition (anger-in) and expression (anger-out) responses regarding a significant emotional event during the day as well as end-of-day pain. Trait anger inhibition and expression were assessed by questionnaire. Multilevel regression analyses were performed.
Results: State anger predicted higher end-of-day pain (p < .001) in half of the patients, but lower pain in one-quarter of patients. State anger inhibition was unrelated to pain. Trait anger inhibition was related to more pain (p = .02). The lowest pain level was observed among patients with high trait anger expression who actually expressed their anger in an anger-arousing situation (p = .02).
Conclusions: Our study suggests that anger and a general tendency to inhibit anger predicts heightened pain in the everyday life of female patients with fibromyalgia. Psychological intervention could focus on healthy anger expression to try to mitigate the symptoms of fibromyalgia.