Obsessing over loneliness is a key factor in the development of depression

According to data from the latest report from the State Observatory of Unwanted Loneliness (SoledadES), corresponding to the year 2024, one in five people in Spain suffers from loneliness, and of these, almost 70% say they have been in that situation for more than two years. The feeling of loneliness is especially common among young people. The prevalence is 34.6% in people between 18 and 24 years of age, and 27.1% in the age group from 25 to 34.

“The fact that one in five individuals experiences feelings of loneliness is worrying and represents a significant challenge for both public administrations and society in general,” says Elvira Lara, a researcher at the Department of Personality, Assessment and Clinical Psychology at the Complutense University of Madrid and co-author of Solitude(s): a study of a global phenomenon (in Spanish). Her opinion is shared by Joan Domènech, a researcher at the Sant Joan de Déu Research Institute (IRSJD), who believes that loneliness is “a social problem” resulting from a set of political, social and economic factors “that moderate, among other aspects, our chances of establishing satisfactory social relationships.”

This inability to establish satisfactory social relationships and the resulting experience of loneliness can, according to Lara, increase the risk of developing mental disorders, worsen their evolution and complicate the prognosis, especially when prolonged over time: “Its relationship with depression has been widely studied, since loneliness can be both a risk factor and a consequence or even a symptom of depression. Loneliness and depression are deeply interconnected and can even overlap.”

Domènech has spent years studying in depth this direct relationship between loneliness and depression. According to a study he led in 2021, unwanted loneliness increases the probability of developing depression fivefold. “The duration of loneliness is decisive in assessing its impact on the probability of having depression. Transient loneliness can have an adaptive function by encouraging the search for new social relationships or the improvement of existing ones. In contrast, chronic loneliness does not have this adaptive function,” he explains.

According to a study by the Rise Center for Emotional Health Research at Sant Joan de Déu, funded by La Caixa Foundation and whose final results will be presented in April, nearly half of cases of loneliness are chronic. And as Domènech points out, people with chronic loneliness often have negative attitudes and expectations about their own loneliness and a higher incidence and recurrence of depression.

The reference to these “negative attitudes and expectations” is important and could have a direct relationship with the higher prevalence of depression. In fact, according to the results of a recent study published in Nature Mental Health, loneliness is more likely to cause depression if the person who feels lonely cannot stop thinking about it. In other words, rumination on the feeling of loneliness would be a key factor in modulating the loneliness-depression relationship. “The novelty that our findings bring to the existing scientific evidence lies in revealing that ruminating on the feeling of loneliness is the key underlying factor that explains the adverse effects of loneliness in the generation of depression,” says Tatia M.C. Lee, lead author of the study.

Lee, Chair Professor of Psychology and May Professor in Neuropsychology at the University of Hong Kong, explains to EL PAÍS that the construct of loneliness that they chose as the object of study was “perceived loneliness,” which means that it is a subjective feeling. “A person who is alone does not necessarily have to feel lonely, while another person who is surrounded by people may feel lonely. In other words, loneliness increases when the gap between desired and real social connections widens,” she argues. For this reason, Elvira Lara adds, people who choose solitude do not experience a conflict between what they want and what really happens in their lives, and so “they do not perceive their situation in a negative way; emotions such as frustration, rejection, fear or sadness do not emerge.” And neither does rumination.

“Rumination puts the emphasis on suffering because it reinforces negative ideas or interpretations, leads to hopelessness and increases or maintains discomfort,” says the UCM researcher. This expert cites the American neuroscientist and psychologist John Cacioppo, who died in 2018, whose research revealed that people who experience loneliness “tend to interpret their social interactions negatively, which can generate insecurity, low self-esteem, pessimism — such as the belief that “nothing I do will change my situation” — and isolation, reinforcing the idea present in rumination.”

Joan Domènech, for his part, feels that the results of the study are “consistent” with previous evidence about the experience of chronic loneliness. “This experience is frequently accompanied by maladaptive biases in the perception of social contacts and negative attitudes about loneliness itself or expectations of improvement,” he adds.

Targeted therapies

For Lee, the results of the study suggest that therapies to address loneliness should focus on reducing ruminative thoughts of loneliness “to minimize the adverse effects of unwanted loneliness.” This reflection is shared by Elvira Lara, for whom the conclusions of the research show that interventions focused on promoting social connection “may be insufficient” for some people who experience loneliness. “According to the results of this study, we should address ruminative thoughts, that is, repetitive and negative ideas that reinforce the feeling of isolation. Working to change distorted interpretations, pessimism and hopelessness is essential, since these factors are linked to depression,” she argues.

“The study adds to the evidence that highlights the need to focus on the individual level of loneliness, that is, to address the psychological aspects related to social cognition in order to overcome feelings of loneliness,” says Joan Domènech. However, he adds, these actions should be complemented by addressing the community level of loneliness. “It is necessary to increase the chances that people who feel lonely can maintain satisfactory social relationships,” he points out, noting that epidemiological studies carried out by the IRSJD through its Healthy Age project show that public services, urban environments, social cohesion and socioeconomic conditions are “key aspects” that shape feelings of loneliness and the mental health of the population.

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