11/07/2017 10:13 BST | Updated 11/07/2017 10:13 BST

What's The Point In Being Positive?

Professor George Lewith* was a doctor who was famous for being kind and optimistic with his patients. In the early 1980s Lewith's colleague Bruce Thomas said positivity might give patients a good feeling but it didn't have any health benefits. In response, Lewith challenged Thomas to do a trial comparing his encouraging style with Thomas' (apparently sometimes grumpy) style. Thomas accepted, hoping to prove that Lewith was wrong.

To prepare the trial, Thomas took a stack of cards and wrote positive on half of them and negative on the other half. He shuffled the cards and put them in a drawer beside his desk. As patients came to visit, he first checked to see whether they had a life-threatening illness that needed referral to a specialist or an ambulance. If they did, he referred them or called an ambulance. Otherwise, he drew a card from the drawer.

• If he drew a 'positive' card he said he knew exactly what was wrong with them. If they didn't need any medicine, he told them confidently that they would be better in a few days. If they needed medicine, he said it would definitely make them feel much better very soon.

• If he drew a 'negative' card, he told patients, 'I cannot be certain what is the matter with you.' If no treatment was prescribed he added, 'and therefore I will give you no treatment.' If a treatment was prescribed he said, 'I am not sure that the treatment I am going to give you will have an effect.'

As a back up plan, he told patients to call him if anything changed. He treated 100 patients with a negative consultation and 100 with a positive consultation. In the end he found that 64% of the patients who received positive consultations got better within two weeks whereas only 39% of the patients with negative consultations got better. He published his results in a 1987 article called 'General practice consultations: is there any point in being positive?'

There were problems with the trial, especially lack of blinding. Since Dr. Thomas knew which patients got the positive consultations, this could have influenced the results. But since Thomas' study, dozens of higher quality studies have been done with many different kinds of outcomes, and it has become difficult to doubt the results. Our recent mega-study with 12 randomized trials confirmed that doctors who use positive language reduce patient pain by a similar amount to drugs. Other trials show that positive messages can:

• help Parkinson's patients move their hands faster,

• increase 'peak flow' (a measure of how much air is breathed) in asthma patients,

• improve the diameter of arteries in heart surgery patients, and

• reduce the amount of pain medication patients use.

The way a positive message seems to help is biological. When a patient anticipates a good thing happening (for example that their pain will go away), this activates parts of the brain that help the body make its own drugs like endorphins. A positive doctor may also help a patient relax which can also improve health.

To be sure, even positive messages can be bad if overdone. Some serious illnesses don't get better, so telling patients with these illnesses they will get better is a lie. However even in these cases, patients like to be offered hope. In fact palliative care doctors who work with dying patients dying emphasize how important it is to communicate in an honest yet hopeful way. This means being honest about the disease, and at the same time help them plan for the things that they can accomplish, such as a last visit with their grandchildren.

Overdoing positive messages can be done but the opposite--negative language--may be just as bad.

Harm caused by negative messages

When doctors say negative things it can increase pain. In one study of patients about to receive an injection, doctors either gave a negative message ('your arm may sting a little') or a neutral message ('your arm may feel tingly'). The pain was 10% higher in the patients who received a negative message. Harms caused by negative messages has been demonstrated in numerous other trials.

In the end...

... George Lewith was right: there is a point in being positive. For doctors, communicating optimism will benefit most patients. If you're not a doctor then being positive (and avoiding negative thoughts) can also benefit you. Studies show that learning to see our problems in a more positive light can improve well being. Just the other day I recommended a positive thinking exercise to a friend. My friend was sceptical and asked: 'How sure are you this stuff works?'

'I'm positive,' I replied.

*Sadly, Professor Lewith passed away peacefully soon after I wrote the first draft of this newsletter. He was happy that I wrote it, and his surviving immediate family have given me permission to publish this.