Loneliness may make cold symptoms feel worse

"Colds feel worse to lonely people," The Guardian reports. A US study, where participants were infected with the cold virus, found people who said they felt lonely also reported more severe symptoms – even though an objective measure of how bad their cold was didn't find the same association.

This US study involved around 200 people who filled out questionnaires on loneliness and their social network. They were then given a cold virus through nasal drops and were quarantined for the next five days in a hotel.

The researchers looked at how those infected with the virus went on to report symptoms. They found that those who had scored highly on loneliness were more likely to report worse cold symptoms but were actually no more likely to catch a cold.

Size and diversity of social network did not seem to have an effect on perception of cold symptoms. Instead it was the people's perception of whether or not they felt lonely that seemed more important when it came to self-reported cold symptoms. So people may have lots of social contacts but still feel socially and emotionally isolated from others.

The results of this study reinforce the point that loneliness can have an impact on health outcomes. A 2013 study, we discussed at the time, found social isolation was even linked with an increased risk of death in older people.

There are ways you can connect with others, even if you live alone and find it hard to get out. Read more advice about overcoming loneliness.

Where did the story come from?

The study was carried out by researchers from Rice University, the University of Houston and the University of Delaware, all in the US. The study was funded by a range of institutes in the US, including the National Center for Complementary and Integrative Health and the National Institute of Allergy and Infectious Disease.

The study was published in the peer-reviewed journal, Health Psychology, and is open-access, meaning it is available to read online (PDF, 86kb).

The UK media's reporting of the research was generally accurate. The reporting pointed out that being lonely did not increase the likelihood of getting a cold, but as the Daily Mail acknowledged, lonely people "reported a greater severity of symptoms".

What kind of research was this?

This was a case series study, meaning there was a defined group of people who participated in the study and all received the same intervention, in this case infection with rhinovirus 39 (RV39), a common cold virus.

They were all followed over five days in quarantine to see whether those who reported being more lonely at the start reported worse cold symptoms than those who said they were not lonely.

This type of study cannot prove cause and effect, that reporting feeling more lonely made people more likely to report worse symptoms. Tiredness, for example could contribute to reporting both.

What did the research involve?

The researchers investigated the effect of feeling lonely on self-reported symptoms of a cold among 213 healthy participants aged between 18 and 55, who filled out questionnaires and were given nasal drops containing RV 39 (a common cold virus) before staying in quarantine for five days.

They were asked to fill out a questionnaire on both loneliness and social isolation at the start of the study.

Participants reported their perceived loneliness on the Short Loneliness Scale, which asked about their relationship with others when answering three questions:

In general, how often do you feel that you lack companionship?
In general, how often do you feel left out?
In general, how often do you feel isolated from others?

Participants were asked about the size and diversity of their social network using the Social Network Index, which reported on:

participation in 12 types of relationship (such as spouse, parents, children, friends)
social network size was determined as the sum of all people the individual had contact with at least once every two weeks
the number of high contact social roles at least once every two weeks was also assessed (such as spouse, parent, friend)
social network diversity was the sum of all high contact roles

Participants were also tested for antibodies known to be released due to a cold viral infection.

Participants self-reported cold symptoms every day, including runny nose, sneezing, sore throat, nasal congestion, headache, chills or malaise at the beginning and over the five days in quarantine. The Jackson scoring system was used, where participants rate the severity of eight symptoms over the past 24 hours.

Also, somebody had the unenviable task of assessing the severity of each participant's cold by collecting and weighing any mucus they produced.

What were the basic results?

Of the total sample of 213, 159 became infected with the virus.

Those infected were analysed in greater detail:

Lonelier people reported more severe cold symptoms than less lonely people. These results remained even when accounting for confounders such as age, sex, education, income, marital status and body mass index.
Loneliness was linked to more severe self-reported cold symptoms, independent of social network size and social network diversity.
Patients who were lonely were no more likely to get infected with the virus than less lonely participants, even after adjusting for demographics, season of participation, depressive affect and social isolation.
Social network size did not predict severity of cold symptoms and neither did number of social roles.

How did the researchers interpret the results?

The researchers concluded that "the perception of loneliness is more closely linked to self-reported illness symptoms than objectively measured social isolation. Assessing psychosocial factors such as loneliness when treating and evaluating the common cold could contribute to health care practitioners' understanding of their patients' experiences with acute illness."

Conclusion

This study shows that when people are infected with a common cold virus, there seems to be an association between how lonely people say they are and the self-reported severity of their cold symptoms.

However, loneliness did not make people more likely to get a cold in the first place.

From the findings in this study, it seems that the quality of social relationships and the feeling of loneliness are more important than the quantity of relationships and the social roles people play.

A possible ironic consequence of the social networking age is that some people may have lots of "friends", via Facebook, Instagram and Twitter, but lack actual emotional engagement with others.

There are some important considerations to bear in mind:

As the authors acknowledge, loneliness did not necessarily cause the perception of worse symptoms. Other factors such as lack of sleep might affect their response to the virus and therefore reporting of symptoms.
The specific mechanisms behind the link between loneliness and reported cold symptom severity was not investigated.
Loneliness was only tested at the beginning of the study and it may be that loneliness levels change over time for some people. Some of those reporting worse symptoms may no longer have been feeling so lonely.
The study was done in the US on healthy young to middle-aged adults. It might be that this group have a higher or lower loneliness level than other groups, so the findings may not apply to the entire UK population.