The pandemic set off a renewed focus on social isolation and how it affects people’s mental health. Now, a new study has found that eight hours of loneliness can increase fatigue as much as going eight hours without food in certain people, according to Science Alert.
A lab test and field experiment by researchers from the University of Vienna in Austria and the University of Cambridge in the UK showed that people who live alone or who enjoy social interactions are the most likely to be affected by social isolation. Moreover, the decrease in energy is a result of changes in the body's homeostatic response, where the lack of social connection triggers a biological reaction. The "social homeostasis" hypothesis suggests that there is a dedicated homeostatic system that autonomously regulates people’s need for social contact. However, information about the psychological responses to social isolation is lacking, according to a press release by the University of Vienna.
For the study, 30 female volunteers spent eight hours in the lab without social contact or without food or with both social contact and food on three days. Throughout the day, they indicated stress, mood, and fatigue as well as physiological stress responses, such as heart rate and cortisol, which were recorded by the scientists. These results were compared with findings from a study conducted during the lockdown in Austria and Italy in the spring of 2020 wherein 87 participants had spent at least eight hours in isolation and their stress and behavioural effects were assessed for seven days.
"In the lab study, we found striking similarities between social isolation and food deprivation. Both states induced lowered energy and heightened fatigue, which is surprising given that food deprivation literally makes us lose energy, while social isolation would not", first authors Ana Stijovic and Paul Forbes said in the statement. The finding was supported by data obtained during the lockdowns which showed that participants who lived alone during the lockdown and who were generally more sociable had lower energy on days on which they were isolated.
The authors said that the fact that this effect can be seen even after a short period of social isolation suggests that low energy could be a 'social homeostatic' adaptive response, which in the long run can become maladaptive.