Pain Catastrophizing and Your Brain

This was originally posted at bodyinmind.org To see the original article please click here.

Experts agree that the experience of pain is influenced by a large number of biological, social, and psychological factors.  The state of our physical body, the amount and quality of support we get from our family and friends, and our beliefs about pain all work together to influence the intensity and quality of all of our sensations, including pain.  Of all of the psychological factors that have been studied and shown to be associated with pain and its impact on our lives, the single most consistent (and to date – among the strongest) factor associated with pain is catastrophizing [1-3].

Catastrophizing can be defined as extremely negative thoughts and beliefs about pain.  They include such thoughts as “It is terrible!”, “It is never going to get better”, and “I can’t stand this pain any more”.  Researchers have not only found that these types of thoughts are consistently associated with current pain, but that when people with chronic pain think such thoughts, this is followed by increases in pain and suffering [4, 5].  Thus, while catastrophizing thoughts have not yet been proven to always lead to more pain and suffering, all of the evidence we have so far is consistent with the theories that argue that catastrophizing about pain makes things worse.

Because of the role that catastrophizing is thought to play in pain and pain-related suffering, we are very interested in understanding what can lead to more (or less) catastrophizing.  We recently published a study that was designed to examine one factor that might underlie the development and maintenance of catastrophizing: the relative activity level of two specific areas of the brain [6].

Our reasons for looking at brain activity as a predictor of catastrophizing were as follows.  First, we know that there is a tendency for activity in the front right part of the brain (so-called “right anterior” area) to be involved in some “negative” feelings (like sadness and anxiety) and a tendency to slow down or withdraw, and activity in the front left part of the brain (actual brain region) to be involved in more “positive” feelings (like optimism, joy, and hope) and a tendency to engage in approach behaviors [7].  Second, we know that catastrophizing thoughts are associated – sometimes very strongly – with negative feelings and withdrawal.  Finally, the amount of a certain type of brain wave (so-called “alpha” waves on electroencephalogram or EEG) in an area of the brain is associated with less activity in that brain area, because the presence of this activity is associated with the release of chemicals in the brain that inhibit activity.

Based on all of these ideas, we hypothesized that if we measured (1) brain waves (using EEG) just over the right and left front areas of the brain at one point in time and then (2) catastrophizing thoughts two year later in a group of individuals with chronic pain, we would see more alpha (i.e., more suppression of activity) in the left front areas of the brain, relative to the right, among those with more catastrophizing.  Measuring brain waves is tricky, because so many things (including what you are feeling at the time of assessment, whether and how much coffee you have drunk, how much sleep you had) impact upon EEG.  So, in order to help ensure that we had a good and stable measure of brain activity, we performed five EEG assessments, with each one more than a week apart, and then averaged the amount of “alpha asymmetry” (that is, a ratio of left to right frontal alpha activity) across the assessments.  We then correlated this alpha asymmetry score with the measure of catastrophizing that we assessed two years later.

Our study hypothesis was supported.  Individuals with more alpha asymmetry (reflecting greater left than right sided frontal alpha; that is, a relative suppression of left frontal activity) reported more subsequent catastrophizing.  The findings are consistent with a model hypothesizing that brain activity in the front of the brain might make people with chronic pain more vulnerable to the development of catastrophizing thoughts, and therefore how much they might suffer from pain. We think that this finding is interesting in and of itself, because it helps us to understand how activity in the brain might (potentially) influence our response to chronic pain.  One of the strengths of this study is that the measure of brain activity was assessed before (well before, two years) the measure of catastrophizing, making it difficult to argue that catastrophizing assessed two years later “caused” the brain activity two years previously.  Still, it is important to acknowledge that the alpha asymmetry which was found to predict might or might not directly influence the development of catastrophizing; it remains possible that it merely reflected a process that is related to catastrophizing.  Research is needed to examine the effects of procedures that influence EEG activity on catastrophizing to determine the role that alpha asymmetry might play in this process.

More importantly, if this finding turns out to be reliable (that is, if other researchers using similar strategies get the same or similar results), it suggests some potentially interesting and innovative ways to treat pain. For example, it may be possible to “activate” the left frontal areas of our brain or “inhibit” the right frontal areas of our brain in order to catastrophize less – or to think more positively about pain. This could be accomplished by changing what we do (active exercise as an “approach” behavior that could activate left frontal areas), what we think (envisioning a positive future), or even how we feel (engaging in activities that bring us pleasure or that are meaningful to us).  There are even more direct ways that are being developed to activate or inhibit brain activity via low voltage electric or magnetic stimulation.  These “treatments”, perhaps even in combination with changes in behavior, thoughts, or feelings, could potentially influence catastrophizing.

As alluded to previously, because this was a correlational study, the results do not prove that the amount of left versus right frontal activity causes catastrophizing.  However, the findings are consistent with the alpha asymmetry hypothesis, and indicate that more research to explore and test this hypothesis further is warranted.  Ideally, research in this area will help us better understand how catastrophizing is maintained, and help us identify ways to decrease catastrophizing responses when they are posing problems for people with pain.