Lonely people are more likely to feel worse cold symptoms compared to others who do not feel so lonely, according to researchers from the University of Houston and Rice University.

They quarantined 159 participants infected with the cold virus in a hotel with no visitors allowed. Then, they were assessed on a loneliness scale, and their social isolation level was analyzed. Out of the ones who became sick from being exposed to the virus, those that were classified as lonely people were 39 percent more likely to suffer from worse symptoms.

Cold Symptopms, Loneliness
A new study has found a relationship between cold symptoms and loneliness. Image credit: Mantality.

Feeling lonely makes you feel worse when sick

In the study titled “Loneliness Predicts Self-Reported Cold Symptoms After a Viral Challenge,” researchers show that loneliness is a factor known to cause a poorer state of health, although there is not much information regarding how patients are affected by their symptoms as reported by themselves.

Citing reports that highlight loneliness and social isolation as unhealthy factors, researchers first focused on marking the difference between the two.

Cold Symptopms, Loneliness
Social isolation may be crucial when analyzing a patient’s risk to develop worse cold symptoms. Image credit: Azure Standard.

For starters, social isolation is quantifiable and is reflected by the sheer size of one’s social network and how often one delves in social contact. Previous studies have proven that socially isolated people are at a higher risk of suffering from cardiovascular disease and higher mortality. Also, depression appears to be deeply linked to social isolation.

On the other hand, people with reduced social networks could be considered to be isolated, but that does not mean that they are lonely. In contrast, lonely people can have relatively large social networks, which goes to show that loneliness is based on the quality of personal relations rather than their amount. This led researchers to believe that loneliness and social isolation may have different consequences on the patient’s state of health.

How the study took place

More than studying a concrete disease, researchers tried to link psychosocial factors and symptoms of illness as reported by the patient. They posted advertisements for healthy people aged 18 to 55, without any allergies or diagnosed psychological illnesses. The initial set of patients consisted of 213 healthy participants, out of which 159 remained in the study due to incomplete data sets.

They were given nasal drops containing RV39, a common cold virus, after which they were quarantined for five days in a hotel. No visitors were allowed on the premises, and they had to stay on the specific floors of the hotel that researchers settled for the study. The only social interaction allowed was among study participants for brief periods of time, as patients were prohibited from entering the room of others to avoid transferring the infection.

Cold Symptopms, Loneliness
Image credit: Black & Kletz Allergy.

28 days later, researchers collected blood samples from the patients and paid them $1,060 for completing the study.

To rate their state of depression, participants were presented with 14 words referring to how they could feel on a day-to-day basis, each of them on a 0 to 4 scale. The composite depression score was determined by taking the median of one “sad” and one “unhappy” item on the survey, which appears to be the most accurate adjectives when it comes to describing depression.

A different approach was considered to assess loneliness, as it was measured with the Short Loneliness Scale. The scale has the participant think about their relationship with other people, such as friends, family, or casual acquaintances. Then, they are asked to answer on a frequency scale from 0 to 4. For example, they were asked “How often do you feel that you lack companionship?” or “How often do you feel left out?”

For social isolation, researchers used the Social Network Index, which analyzes 12 types of social relationships. The size of the social network was reflected in the number of people the participant had contact with in the last two weeks, taking into account high contact social roles, such as those of a spouse or a parent.

Lastly, the patients were asked to self-report on a daily basis their cold symptoms over the course of their quarantine.

It seems that loneliness is an important risk factor for the severity of self-reported cold symptoms. Compared to participants who were less lonely, lonely ones were more likely to report a higher severity of cold symptoms, all taking into account age, sex, education, depressive affect, BMI, among other personal statistics.

“What makes this study so novel is the tight experimental design. It’s all about a particular predisposition (loneliness) interacting with a particular stressor. Doctors should take psychological factors into account at intake. It would help them understand the phenomenon when a person comes in sick,” stated co-author Chris Fagundes, Ph.D.

Curiously, social network size did not seem to affect the results, suggesting that loneliness may be a predominant factor regarding the experience of acute illness. Researchers also note that lonely individuals were just as likely to become infected with the RV39 virus.

Source: American Psychological Association