Associations amongst poverty, loneliness, and a defensive symptom cluster characterised by pain, fatigue, and low mood

Humans are a socially interdependent species, making social cues important inputs for allostatic systems that protect the body from harm and regulate energetic resources. Perceived social isolation is associated with increased pain, fatigue, and depression. Other research has shown that pain and depression are more common in individuals experiencing low socio-economic status, and that social relationships are especially important for buffering the negative health effects of low socio-economic status. We thus hypothesised that loneliness and poverty would interactively predict a symptom cluster of pain, fatigue, and low mood in a cross-sectional sample of 24,805 respondents to the European Social Survey 7 spread across 20 countries. We show that lonely individuals score higher on the symptom cluster, and that as income increases, scores on the symptom cluster decrease. We also show an interaction between loneliness and income on the symptom cluster: the association of loneliness with the symptom cluster is stronger amongst those on lower incomes. Finally, we show that those from lower income deciles are much more likely to feel lonely, despite no differences in reported time spent socialising. Our results show that both loneliness and low income predict higher scores on the symptom cluster, and that social relationships are especially strong buffers of the symptom cluster for individuals experiencing poverty. We situate these findings in empirical and theoretical research on how and why social environments affect the allostatic processes underpinning the symptom cluster, and we discuss how our findings inform understandings of social and economic gradients in health outcomes.