"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.
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 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".
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.
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:
Participants were asked about the size and diversity of their social network using the Social Network Index, which reported on:
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.
Of the total sample of 213, 159 became infected with the virus.
Those infected were analysed in greater detail:
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."
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:
Read more about practical steps you can take to overcome loneliness and connecting with others.