Interview on IBS and the Brain with Dr. Mayer of UCLA

Hi everyone,

Found this interview on IBS and the brain that I thought you would find interesting. It doesn't mention hypnosis per se but has more to do with the brain and pain. I just thought it FYI. Interestingly, Dr. Mayer wrote back to me that he did indeed study hypnosis in his fellowship!!


Reported May 26, 2008
Overcoming the Pain of IBS (Interview)

Emeran Mayer, M.D., of UCLA, explains why the brain may be to blame for pain felt by irritable bowel syndrome patients.


What is Irritable Bowel Syndrome (IBS)?

Dr. Mayer: IBS, irritable bowel syndrome, is one of the most common chronic functional pain conditions and is also one of the most common complaints that leads patients go to see a gastroenterologist. It is a combination of chronic abdominal pain and/or discomfort with altered bowel habits -- either constipation, diarrhea or a mix of those two.

Is there a known cause of IBS?

Dr. Mayer: Not really. I think we have gotten closer to understanding certain mechanisms that contribute to it but we don’t even know if its one disease or if its symptoms that can come from multiple different etiologies.

How do you normally treat IBS?

Dr. Mayer: There are traditional treatments that have been around for the last 20 to 25 years but very few of them have ever been demonstrated to be more effective than placebo. A few new drug treatments have been developed over the last ten years but unfortunately those had to be withdrawn or put into a limited access program because of rare but potentially harmful side effects. So we are pretty much at square one in terms of new medications. There are things on the horizon but what is currently available for the patient is very limited.

Explain to me how the brain prepares for pain.

Dr. Mayer: Pain happens like a reflex when something bad happens to your body. We are beginning to understand that the pain experience in humans is a very complex experience with sensory, emotional, cognitive, and memory components. The expectation of pain is one important component, and that is where that study is.

Tell me a little about your study.

Dr. Mayer: We enrolled female subjects, both healthy control subjects and patients with IBS, and excluded patients with psychiatric disease or psychological comorbidity. The study had two components -- one was the expectation condition, indicated by a queue light in the scanner, signaling an imminent adversive distension of the colon within one to three seconds. We recorded the brain’s response, both during the queue light and the actual distention, the latter being moderately unpleasant.

The patient would actually feel something during the second part of the study?

Dr. Mayer: They will feel something during the second part, meaning the distension part of the study, and this would be repeated many times. Then the average of these brain responses are analyzed.

What differences did you see between the two?

Dr. Mayer: There are fundamentally different responses to the expectation by the queue and the actual experience. But we found that these two responses are related. During the expectation -- and we had hypothesized this -- the brain prepares, depending on the stimulus, for what it thinks is going to happen. So if somebody knows this is a very strong stimulus, it’s inescapable and there is nothing you can do about it, like in the scanner, the normal brain would turn down the gain of the sensory systems and the emotional pain amplification system. This also happens when you are faced with an unavoidable situation and there is no advantage to becoming extremely sensitive --You want to minimize the damage. The response is different if the expected pain is variable, you don’t know if it’s just mild or barely perceptible, and if you don’t know when it is coming. In this case, the brain wants to do the opposite thing -- it wants to detect it as quickly as possible and determine if it is going to be something dangerous or not. The hypothesis we had was confirmed by the study because we found that healthy control subjects who know when something is going to be unpleasant and know that they cannot run away from it and don’t have any other alternatives, decrease activity in both sensory brain regions (reducing the sensory intensity of pain) and also in emotional regions that we know play a role in pain amplification. The more anxious, the more emotional somebody is, the more severe the experienced pain is. For example, going to the dentist isn’t always a good experience but the adult person has learned to cope with it. To cope with it, you train your brain to turn down the strength of the amplification -- the child who is terrified of the dentist does the opposite -- rather than turning it down, the child may actually increase the activity in those circuits.


How does a person with IBS react?

Dr. Mayer: To our surprise, the main difference we have found was that IBS patients failed to turn down the gain. They failed to turn off the sensory regions and they failed to turn off the emotional regions involved in anxiety or anticipatory anxiety. The brain fundamentally did not show the normal, what we call adaptive response to the situation. At first glance, this seems trivial, but it confirms -- actually relates to -- a much larger body of the literature about symptom-related fears or symptom-related anxiety which seem to be play a big role in many chronic pain disorders. The relationship between symptom-related anxiety and chronic pain has been shown in many non-imaging survey studies. Patients who have chronic pain disorders have much higher fears and anxieties related to what could happen in a given situation related to their symptoms. For example, what could happen if an IBS patient goes out for dinner -- this discomfort does not start at dinner -- it starts hours or minutes before the actual dinner, when the brain starts turning on the gain, the anxiety and emotional circuits, which in turn amplifies the discomfort when the meal is actually taken in.


Are your findings biological?

Dr. Mayer: Yes, this is always the big question. Most people like to squeeze you into traditional dichotomy -- is it psychological or is it real, meaning biological? We refuse to accept that dichotomy because the more we use imaging to look at brain function, the more we realize that every brain function, emotions, cognitions or pain response, has a biological basis. What we saw in this study is therefore a neurobiological response that is different in patients. We know that because we have other studies going on that look at what are the neurotransmitters underlying this -- it seems the dopamine signal system in the brain is involved in its difference. We also look at, for example, genetic factors -- how they might predispose an individual to have this response that does not turn off the gain. Why would there be a genetic basis for something like this and why would it be between 15 and 20 percent of the population who have these syndromes? It’s most likely that, from an evolutionary viewpoint, it is advantageous to avoid physical damage by not turning off the gain of the system, and detecting the pain stimulus early. Such an individual is hypervigilant and maximizes its sensitivities. You can ask yourself: what is better for you: to miss the appropriate response once if something really bad happens to you, or if you are hypervigilant and run away nine times too often. So we think that there may be a genetic basis for this kind of difference in the brain’s response.


Now that you know that, what does it mean for treating IBS down the road?

Dr. Mayer: Treatment takes several components. One is that we know certain patients respond well to medications that aim to decrease the activity in arousal circuits within the brain and can either manifest as anxiety or anticipatory anxiety or abnormal expectation -- that is the pharmacological implication. But maybe more interesting and relevant is the cognitive behavioral strategies where patients are trained to deal with situations differently. If you show this information to a patient and say we are going to teach you skills to respond differently to a situation, it can be very powerful. Surprisingly at the moment, I didn’t mention it earlier, cognitive behavioral therapies are the most effective treatments for patients who are willing to undergo it -- not general psychotherapy, not psychoanalysis, but really retraining the brain to respond differently to expected stressors, including pain.