A study in Germany found that people who reported higher levels of loneliness tended to have fewer social relationships. This association was present in both depressed and non-depressed individuals, but the correlation was significantly stronger in depressed individuals. The paper was published in BMC Psychiatry.
Loneliness is a feeling of sadness or distress that occurs when a person feels socially or emotionally disconnected. It is not the same as simply being alone because a person can be alone without feeling lonely. People can feel lonely even when they are surrounded by others.
Loneliness usually reflects a gap between the relationships a person wants and the ones they actually have. It may be temporary, such as after moving to a new location or losing contact with friends. Additionally, if these feelings continue for a long time, they may become chronic. Chronic loneliness is associated with worse mental health conditions such as depression and anxiety. It can also affect your physical health by increasing stress and impairing your sleep and overall health.
Study author Valeria Koppert and colleagues wanted to investigate the relationship between the number of social relationships a person has and feelings of loneliness. In particular, they wanted to compare the strength of this association in people suffering from depression and those without depression. They noted that depressed people tend to feel more lonely than healthy people, and wanted to know whether they also had fewer actual social relationships than non-depressed people.
The study authors analyzed data from the German Depression Barometer, an annual national survey of people aged 18 to 69 in Germany. The study was carried out by the German Foundation for Depression and Suicide Prevention. Data was collected from late August to early September 2023.
The analysis is based on a total of 4,042 participants. Of these, 1,221 reported a lifetime diagnosis of depression, and 2,821 were considered healthy. Women made up 61% of the depressed group and 46% of the healthy participants.
The survey included questions asking participants whether they had ever been diagnosed with depression and the severity of their current symptoms. Participants also completed a loneliness assessment (11-item De Jong Gilbert Loneliness Scale) and reported number of social contacts. The social contact item asked about the average number of daily personal interactions with other people on a typical weekday.
Results showed that in both groups, more pronounced loneliness was associated with a reduced number of social contacts. However, this inverse association was significantly stronger in the depressed group than in the group of healthy participants.
Supporting previous research, people with a history of depression report significantly higher levels of overall subjective loneliness and less social contact than healthy individuals.
When researchers analyzed the different stages of acute depression, they noticed an interesting pattern. They found that patients’ subjective feelings of loneliness varied widely depending on their current state and spiked during active depressive episodes. However, the actual number of social relationships remained relatively stable across different stages of the disease.
“Our study shows that there is a negative correlation between feelings of loneliness and the number of social relationships in patients with depression,” the study authors concluded. “We find that there is greater variation in loneliness than in number of social relationships when it comes to current depression status.”
Because this study proves that the number of actual social relationships significantly influences depressed patients’ internal feelings of loneliness, the authors suggest that clinical interventions should actively focus on helping patients rebuild their objective social networks, rather than treating loneliness simply as an internal chemical symptom.
This study contributes to the scientific understanding of the association between contact with others and feelings of loneliness in patients with depression. However, it should be noted that the study design did not allow for drawing causal inferences from these results. Additionally, the study relied entirely on a self-reported online survey, meaning the diagnosis of depression was not clinically validated by the researchers.
The paper, “The association between loneliness and the number of social relationships in depression: a cross-sectional study among German adults,” was written by Valeria Koppert, Andreas Czaplicki, and Ulrich Hegel.

