Tag Archives: nocebo effect

Pain in the brain

You don’t just experience pain physically. The amount of pain you perceive is influenced by environmental factors – for example sound, temperature and your surroundings – and psychological factors, such as your thoughts, beliefs, feelings and attitudes.

You feel pain through specialised nerve cell endings called nociceptors .These send signals through your central nervous system, which your brain will interpret.

So how much can your perceptions really affect your pain?

The placebo effect

Your expectations and emotions are powerful. They can have a significant impact on the success of a treatment. You might experience pain relief, or improved symptoms, from taking fake medication or having a fake procedure. This is known as the placebo effect.

In one experiment led by psychologists at the University of Michigan, participants received a placebo that they were told would help reduce pain from painful stimuli such as heat or an electric shock. Images of their brains while in pain showed less activity in the pain-sensitive areas of their brains when they had the placebo, compared with when they didn’t.

If positive expectations can make pain better, can negative thoughts make it worse?

The nocebo effect

Meet the placebo effect’s evil twin! Researchers have found that expecting negative side effects from drugs can sometimes be enough to cause them, even when the drugs are supposedly harmless. This is called the nocebo effect. In one experiment, a group of patients with back pain were asked to do a test. The half that was told it would make their pain worse reported that they experienced more pain.

So how might this change how medics talk about pain and pain relief?

The placebo and nocebo effects have shown the importance of the way you talk about pain. If doctors give negative suggestions, or tell patients too much information about possible side effects, they could increase the chance of the patient experiencing them.

‘Patients who have unrealistically high or very low expectations from a treatment may affect the efficiency of the drug or surgery they are having’ explains Paul Enck, Professor of Medical Psychology at University Hospital Tübingen.

’Probably the best way to address this in future is to speak to the patient about their expectations from the treatment. Choosing the right terms to use may be as important as avoiding giving the wrong information.’

Now we know that our thoughts and expectations can affect our response to pain treatment, can we actively change our emotions to make drugs more effective? And can understanding the effect of a good mood on your pain improve treatments?


‘If we can understand how being in a happy mood, or having positive expectations, reduces pain signals in the brain, we might be able to provide a radically different way to switch off the pain and provide relief,’ explains Irene Tracey, Director of the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB).

But can patients find their own path to pain relief?

‘We have found that even a brief amount of meditation training can make a difference in the experience of pain,’ says Fadel Zeidan from Wake Forest School of Medicine.

‘In one of my experiments healthy volunteers were given a painful stimulus and rated their experience. After four sessions of meditation training, meditating whilst experiencing the painful stimulation reduced pain unpleasantness by 57% and pain intensity by 40%. In contrast, researchers have found that a clinical dose of morphine reduces pain by up to 25%.

‘Clinicians are already using meditation alongside medication to help reduce the amount of drugs patients need to take.’

‘Meditation is not necessarily about reducing the pain sensation, but about changing the perception of pain and relating to it differently,’ says Tim Gard at Massachusetts General Hospital, Harvard Medical School.

‘In one study I used brain imaging to see changes in the brain while meditating and experiencing pain. I found that activity in the brain was different between those who had and had not meditated before. The experience of pain was less unpleasant in those who meditated.

‘I think meditation will play an increasingly important role in chronic pain management, but alongside medicine rather than replacing it completely.’

So the question is; can we really have a drug free future?

‘For something like pain, in particular chronic pain, there is no doubt that a three-way approach – drugs, working with psychologists and physical rehabilitation – is the most successful,’ says Irene Tracey.

‘Pain is both a sensory and emotional experience. A single approach to tackle one element can provide a lot of benefits, but a combined approach really attacks the problem at all the different points at which pain can take hold.’

Future clinicians will need to decide who will benefit most from which combination of approaches. Which approach would you prefer?