Understanding Loneliness

Take our Loneliness Test

Find a therapist near me

No loneliness measure scores well on all three quality dimensions. That's a problem for policy.

The same population can look 20 percentage points more or less lonely depending on the measure.

A traffic light system rates loneliness measures on comparability, validity, and coverage.

Two reports on U.S. loneliness came out in 2025. One said about 41 percent of adults were lonely. The other said about 61 percent. Same country, same year—a 20-percentage-point gap.

These weren't fringe studies. These were experts using established measurement tools. And yet they painted fundamentally different pictures of the same population. If the numbers can swing that much depending on which questionnaire you pick up, what are we actually tracking?

My colleagues and I have been digging into this through the LONELY-EU project, a European Union-funded effort to evaluate how loneliness is measured across all 27 EU member states. We recently published two policy briefs—one on Europe's measurement challenge and one on a quality rating system we developed to address it—and I want to share what we found, because it has implications well beyond the EU.

Loneliness is linked to a 26 percent increased risk of early death. In Spain alone, it's estimated to cost more than €14 billion a year. The UK and Japan have appointed loneliness ministers. The former U.S. Surgeon General has declared it a public health crisis (but see this post as a reminder about it not being an epidemic). The........

© Psychology Today