A new study has concluded that living alone is linked to common mental disorders. The authors have also identified the main driver of this worrying relationship.
Some common mental disorders (CMDs) include mood disorders, anxiety, and substance use disorders.
According to some studies, almost one-third of people will experience a CMD in their lifetime.
These conditions can have a significant impact on the individual, of course, but due to their high prevalence, they also affect society at large.
Due to the widespread influence of CMDs, scientists are keen to understand the full range of risk factors that feed into mental health.
In recent years, scientists have investigated whether living alone might be one such risk factor.
A new study, the results of which now appear in the journal PLOS ONE, takes a fresh look at this question. The study authors conclude that there is a link between living alone and CMDs. They also find that it affects all age groups and sexes, and that primarily, loneliness is the driver.
The number of people living alone is steadily growing throughout much of the Western world; this is due to a number of reasons, including the aging population, people tending to get married at an older age, and increased divorce rates.
Researchers have already looked at the relationship between CMDs and living alone, but most have focused on older adults, so their findings may not apply to other age groups.
Previous work has also not quantified how other factors influence this relationship; for instance, people who live alone are more likely to be overweight, smoke, use drugs, and lack social support. So which of these, if any, is the main driver of CMDs?
The authors of the new study aimed to fill in some of these gaps. They looked for links between living alone and CMDs in general, and they investigated which factors seemed to be influencing the relationship.
Looking at the data
To investigate, scientists from the University of Versailles Saint-Quentin-en-Yvelines in France analyzed data from 20,503 adults, ages 16–74, living in England. The data came from three National Psychiatric Morbidity Surveys that experts conducted in 1993, 2000, and 2007.
Participants completed Clinical Interview Schedule-Revised questionnaires, which assessed whether they had experienced neurotic symptoms during the previous week.
The surveys also collated data on a range of variables, including height and weight, level of education, employment status, alcohol and drug use, social support, and feelings of loneliness.
As expected, the authors found that the number of people living alone has steadily grown. In 1993, 8.8% lived alone. This is compared with 9.8% in 2000 and 10.7% in 2007.
Their analysis also showed that across all age groups and sexes, there was a significant association between living alone and having a CMD. The size of this relationship was fairly similar across the three surveys.
CMDs were more common in those living alone than those not living alone:
- 1993: 19.9% vs. 13.6%
- 2000: 23.2% vs. 15.5%
- 2007: 24.7% vs. 15.4%
The trouble with loneliness
When the scientists delved deeper into the relationship between CMDs and living alone, they found that loneliness explained 84% of the association.
During what some experts call a "loneliness epidemic," this finding is particularly important. Similarly, because ill mental health is a growing concern, understanding the risk factors associated with CMDs might help turn the tide.
Of course, not everyone who lives alone is lonely. However, for those who are, interventions to tackle loneliness are available. These may include talking therapies, social care provisions, and animal-based interventions.
The next and most challenging step is to find ways to ensure that people in need get access to these tools.
The researchers acknowledge certain limitations to the study. For instance, this was a cross-sectional study, meaning that it looked at a snapshot of people at one point in time. The authors call for longitudinal studies to ascertain how this relationship might play out over time.
As with any study of this nature, assessing cause and effect is not possible: Did a person develop a CMD because they lived alone, or did they develop a CMD and then decide to live alone?
Or, perhaps, someone with a predisposition for CMDs is more likely to want to live alone. As ever, scientists will need to carry out more work to fill in the gaps.
Earlier findings back up these results, but the new findings also go a few steps further; they show that the relationship between mental health and living alone is stable across time, that the link is not restricted to older adults, and that loneliness plays a pivotal role.