Anger Linked to Pain in Women With and Without Fibromyalgia

From MedscapeCME Clinical Briefs

News Author: Laurie Barclay, MD
CME Author: Charles P. Vega, MD

October 6, 2010 — Anger amplifies clinical pain in women with and without fibromyalgia, and cognitive therapy is effective in the treatment of fibromyalgia, according to the results of 2 studies reported in the October print issue of Arthritis Care & Research, a journal of the American College of Rheumatology.

Previous Evidence Linking Emotions to Fibromyalgia

"We observed that many patients with fibromyalgia experienced negative emotions such as anger and sadness due to their condition, and patients told us that the stress that they experienced daily increased their pain," lead author Henriët van Middendorp, PhD, a senior researcher from the Psychorheumatology Research Group at the Department of Clinical and Health Psychology, Faculty of Social and Behavioral Sciences at Utrecht University in Utrecht, the Netherlands, told Medscape Medical News. "Although many studies have shown that negative emotions and pain are mutually associated, which may only reflect that pain causes negative feelings, hardly any study examined whether negative emotions were able to amplify pain. Previous research had shown that patients with fibromyalgia respond with more pain than healthy people to a variety of physical stressors, but psychological and especially emotional stressors had hardly been studied, [which] made us wonder whether patients would be also hypersensitive to emotional stressors when we would compare them to a sample of women without fibromyalgia."

Additional impetus for this study came from existing literature on anger and especially on anger management in dealing with chronic pain, which suggested that anger could be specifically relevant for chronic pain.

"In a previous study, we have shown that women with fibromyalgia not only experienced negative emotions more frequently and with a larger intensity, but also that they processed and dealt with their emotions in less healthy ways," Dr. van Middendorp said. "For instance, the women with fibromyalgia had more difficulty identifying and describing their emotions and suppressed their emotions more, which are related to worse functioning, including more pain....[In this study], we wanted to compare 2 negative emotions, sadness and anger, to see whether we would indeed find that anger was a 'more painful' emotion than sadness, or whether general negative affect would be responsible for potential pain increases."

van Middendorp Study

In this study, 62 women with fibromyalgia and 59 women without fibromyalgia first recalled a neutral situation and then recalled both an anger-inducing and a sadness-inducing situation, in counterbalanced order. Using repeated measures analysis of variance, the investigators studied the effect of these emotions on markers of pain response, including noninduced clinical pain and experimentally induced sensory threshold, pain threshold, and pain tolerance.

"We found that negative emotions as experienced in daily life are able to increase pain above the already high pain levels in women with fibromyalgia," Dr. van Middendorp said. "Thus, our study strongly suggests that negative emotions may cause an increase of the pain. We did not find that women with fibromyalgia were more sensitive to emotions than women without fibromyalgia; however, because women with fibromyalgia experience negative emotions more frequently than women without fibromyalgia and already have heightened pain levels, the increase in pain due to negative emotions is especially relevant in this patient group."

In response to inductions of anger and sadness, women with fibromyalgia had increased clinical pain reports (P < .001), and both groups had decreased pain threshold (P < .001) and decreased pain tolerance (P < .001). Reactivity to sadness predicted clinical pain responses, whereas reactivity to anger predicted both clinical and electrically stimulated pain responses.

"Because negative emotions are an unavoidable part of life, especially when dealing with chronic pain, it could be worthwhile to focus on trying to change the way patients with fibromyalgia deal with their emotions in order to try to change the impact that negative emotions have on pain," Dr. van Middendorp said. "For instance, teaching patients to recognize their emotions and to express them may decrease the intensity with which the emotions are experienced and — consequently — the impact of these emotions on pain."

Regarding additional research, Dr. van Middendorp recommended comparing pain responses in patients who differ in how they experience and regulate their emotions and examining the effects of positive emotions, such as joy, on pain in patients and nonpatients.

"Because we found more emotional experience and regulation difficulties in women with than without fibromyalgia, it could be that differences in the ability to recall, experience, and express angry and sad events in our study are responsible for the failure to demonstrate that fibromyalgia patients show a greater emotion-induced pain response than the control women," Dr. van Middendorp concluded. "Future research should test techniques to facilitate better emotion regulation, including not only interventions to downregulate emotional experience, such as relaxation, cognitive reappraisal, and exercise, but also techniques to facilitate emotional awareness, experiencing, and processing."

Comment: Forgiveness Interventions Hold Promise

When asked for independent comment, Loren L. Toussaint, PhD, an associate professor of psychology at Luther College in Decorah, Iowa, and a visiting scientist at Mayo Clinic in Rochester, Minnesota, told Medscape Medical News that this was an "interesting and insightful" study with "surprising" findings.

"There is reason to expect that fibromyalgia patients, as compared to healthy subjects, should show a greater pain response to negative emotions such as anger and sadness," Dr. Toussaint said. "First, it could simply be that our expectations are wrong and the emotion and pain connection is more similar than different when comparing fibromyalgia patients to others. A second, and perhaps more viable explanation, is that fibromyalgia patients came to this study with more pain to begin with, [which] might have muted the effect of emotion on pain simply because fibromyalgia patients may not have been capable of experiencing much more pain than what they started the study with."

Because of the experimental design, Dr. Toussaint noted that strong causal conclusions can be made about the effects of negative emotions on pain, but not vice-versa, allowing for speculation on what the benefits for minimizing negative emotions might be.

"The results suggest that negative emotions affect pain experiences in fibromyalgia patients similarly to healthy people, [which] actually holds great promise!" he said. "It suggests that many of the ways of effectively dealing with anger and sadness that have been developed for use in the general population might be effective and applicable with this patient group."

Dr. Toussaint and his colleagues have been developing and testing forgiveness interventions for dealing with a variety of negative emotional reactions to being hurt or offended. Previous studies have also shown that forgiveness education is effective in minimizing negative emotions, promoting positive emotions, and improving health and well-being in the general population.

"These findings suggest that our methods may have an equally powerful effect in fibromyalgia patients," Dr. Toussaint said. "Of course, other methods of anger management and grief counseling may also have beneficial effects. Future research should examine these emotion management methods for their efficacy in helping fibromyalgia patients with emotional adjustment, pain, and other fibromyalgia-related symptoms."

van Koulil study

The second study, by Saskia van Koulil, MSc, from Radboud University Nijmegen Medical Centre in the Netherlands, and colleagues, explored the effects of tailored cognitive behavioral therapy (CBT) and exercise training for high-risk patients with fibromyalgia.

"This is a very strong randomized clinical trial (RCT) assessing the efficacy of tailored CBT in combination with exercise training for high-risk fibromyalgia patients," Dr. Toussaint said. "Studies of this type are difficult to do well and the authors should be applauded for their success in completing this important study."

Study patients were classified into pain-persistence and pain-avoidance groups and then were randomly assigned in groups to either a treatment or a waiting list control condition. Treatment was tailored to the patient's specific cognitive behavioral pattern and consisted of 16 sessions of CBT and exercise training, delivered within 10 weeks.

"It is especially encouraging to see that CBT was tailored to the needs of the patients," Dr. Toussaint said. "Tailoring holds great promise for enhancing the effectiveness of this type of work with fibromyalgia patients. One-size-fits-all therapeutic approaches are not likely to be as effective given the especially wide range of variability in symptoms, intensity, and impairment in fibromyalgia."

At baseline, posttreatment, and at 6 months' follow-up, the investigators measured physical and psychological functioning and the effect on fibromyalgia. A linear mixed model allowed determination of treatment effects.

For the treatment condition vs the controls, there were significant, large, and clinically relevant treatment effects for all primary outcomes. Approximately 60% to 70% of patients receiving the therapy showed improvement in physical functioning (pain, fatigue, functional disability), 55% to 69% showed improvement in psychological functioning (negative mood, anxiety), and 60% showed improvement in fibromyalgia impact on daily life.

"While existing research and therapeutic approaches have emphasized multidisciplinary approaches to treatment, the current findings suggest that tailoring CBT may enhance the relevance and effectiveness of these types of approaches," Dr. Toussaint said. "This should yield improved outcomes, adherence, and treatment efficiency. It is this type of RCT that speaks directly to the varied and multifaceted needs of fibromyalgia patients."

Study strengths noted by Dr. Toussaint include high retention of patients throughout the trial, use of standardized assessments, and robust and clinically relevant statistical results. Two key limitations are lack of blinding, preventing control for expectation biases; and lack of direct comparison of tailored vs nontailored interventions.

Regarding future research, Dr. Toussaint recommended instituting a blind-to-treatment condition, comparing tailored vs nontailored conditions head-to-head, and possibly incorporating a placebo intervention.

"Our results demonstrate that offering high-risk fibromyalgia patients a treatment tailored to their cognitive behavioral patterns at an early stage after the diagnosis is effective in improving both short- and long-term physical and psychological outcomes," Ms. van Koulil said in a news release. "Supporting evidence of the effectiveness of our tailored treatment was found with regard to the follow-up assessments and the low dropout rates. The effects were overall maintained at 6 months, suggesting that patients continued to benefit from the treatment."

The Dutch Arthritis Association financially supported both studies. The study by van Koulil and colleagues was also supported by the Netherlands Organization for Health Research and Development. The authors of both studies and Dr. Toussaint have disclosed no relevant financial relationships.

Arthr Care Res. 2010;62:1370-1376, 1377-1385.

Clinical Context

How much do emotions affect pain perception? That was the clinical question posed by van Middendorp and colleagues in a study from the current issue of Arthritis Care & Research. The study protocol involved 62 women with fibromyalgia and 59 women without fibromyalgia. They were asked to describe an event that made them angry, an event that made them sad, and an emotionally neutral event. The women with fibromyalgia rated their general pain level after each event description, and participants with and without fibromyalgia also underwent an objective measurement of pain tolerance via electrical stimulation of the forearm after recounting each event.

Anger and sadness reduced the threshold for feeling pain as well as the level of pain tolerance, regardless of the presence of fibromyalgia. Moreover, among women with fibromyalgia, the general level of clinical pain increased with the emotions of anger and sadness. The degree of anger and sadness predicted the degree of clinical pain with fibromyalgia.

This study demonstrates how complicated the symptom of physical pain can be, particularly in a difficult illness such as fibromyalgia. Another study by van Koulil and colleagues published in the same issue of Arthritis Care & Research examines the use of tailored therapy to improve fibromyalgia outcomes, and its results are reviewed in the Study Highlights section.