The association between feelings of loneliness and the number of social relationships in depression: a cross-sectional study of German adults

TL;DR

People with depression in Germany report stronger loneliness and fewer social relationships compared to non-depressed individuals, even when they have many social contacts.

Contribution

This study shows that depression is linked to stronger loneliness despite having social relationships, which could inform better treatment strategies.

Findings

Depressed individuals reported significantly higher loneliness (M=6.53) than non-depressed individuals (M=4.30).

Depressed individuals had fewer social contacts (39.2% with 0-4 contacts) compared to non-depressed individuals (20.5%).

The correlation between loneliness and social relationships was stronger in depressed individuals (ρ = -.234) than in non-depressed individuals (ρ = -.132).

Abstract

Depression is a common psychiatric disorder that is associated with both feelings of loneliness and withdrawal from social relationships. However, clinical experience suggests that feelings of loneliness are an integral part of depressive symptomatology and can occur even when a patient has many social relationships. We addressed the following three research questions: 1. How are feelings of loneliness and the number of social relationships associated in people with depression compared with the nondepressed population? 2. Do people with depression have more feelings of loneliness compared with the nondepressed population? 3. Do people with depression have fewer social relationships compared with the nondepressed population?

Cross-sectional data from the German Depression Barometer 2023, a representative survey of the German adult population (N=5196), were analysed. Feelings of loneliness and the number of social relationships were assessed via self-reports.

Feelings of loneliness and the number of social relationships are negatively correlated both in people with a lifetime diagnosis of depression (n=1221, Spearman’s ρ = -.234, p <.001, 95% CI [-.288; -.179]) and in people without a depression diagnosis (n=2821, Spearman’s ρ = -.132, p <.001, 95% CI [-.169; -.094]). The strength of the correlation is significantly greater for people with a lifetime diagnosis of depression (Z=2.99, p <.02). Increased feelings of loneliness are found in people with a lifetime diagnosis of depression (M=6.53) compared with the nondepressed German population (M=4.30). The difference between the two groups is significant, t(4040) = 19.08 , p <.001, d = 0.654. Additionally, fewer social relationships are found in people with a lifetime diagnosis of depression (39.2% with 0-4 social contacts on a normal day) than in the nondepressed German population (20.5% with 0-4 social contacts on a normal day). The difference between the two groups is again significant, U = 1247054,50, Z = -14.44, p <.001, r = 0.227.

Contrary to our expectations, a stronger inverse correlation between feelings of loneliness and the number of social relationships was observed in people with depression than in the nondepressed population. Furthermore, we replicated findings of increased feelings of loneliness and a reduced number of social relationships in people with a lifetime diagnosis of depression. This has possible implications for treatment decisions and intervention programs, namely, that both feelings of loneliness and social relationships should be addressed.

Not applicable.

The online version contains supplementary material available at 10.1186/s12888-026-07915-3.