Living alone and feeling lonely are different

The story in detail

Loneliness describes feeling that relationships are insufficient; social isolation describes limited social contact. Researchers examined both in 277,489 UK Biobank participants initially free of seven major chronic conditions. They modelled years lived without physical disease or mental disorder. People reporting both loneliness and isolation had fewer estimated disease-free years, with a larger difference for mental disorders.

Healthier lifestyles were associated with a smaller gap linked to isolation, but the corresponding relationship for loneliness was not statistically established. These are population estimates, not predictions of how many years an individual will lose. The observational design cannot establish causation. Its useful distinction is that the size of someone’s social network and their experience of those relationships are separate questions.