“It is not good that man should be alone.” And now a new study has suggested that living alone is correlated with having a mental disorder. Louis Jacob from the University of Versailles Saint-Quentin-en-Yvelines has concluded that living alone “is positively associated with common mental disorders, regardless of age or sex.” The study compared survey data (National Psychiatric Morbidity Surveys) from 20,500 individuals aged 16-64 living in England collected in the years  1993, 2000 and 2007 and found the prevalence of common mental disorders was higher in individuals living alone than in those living with others. The difference between this and previous studies is that the latter, although investigating the link between living alone and mental disorders, have generally been confined to elderly populations. These were therefore of less applicability to younger adults. But this study broadened the age bracket beyond those elderly living alone.

And the prevalence of those living alone before their twilight years has increased in recent decades thanks to decreasing marriage rates and lowering fertility. In the three years in which the study used survey data (1993, 2000 and 2007) the prevalence of those living alone in England was 8.8 percent, 9.8 percent and 10.7 percent.

(These figures are comparable to other developed countries. In New Zealand, the number of people living alone has grown from 204,000 in 1986 (9 percent of the population) to 355,000 in 2013 (12 percent of the population). In the future this figure is projected to increase to around half a million in 2023 and comprise 13 percent of the population. In the USA just over 10 percent of the population live alone: there were 35.7 million single person households in 2018.)

In those same years, the rates of common mental disorder (CMD) were 14.1 percent, 16.3 percent and 16.4 percent. Across the three sample years, for all ages and for both sexes there was a positive association between living alone and CMD. Now this of course does not mean that you are more likely to get a mental disorder due to living alone. People with CMD may be more likely to live alone.  But it does not seem to me surprising that if social animals such as humans live alone, this would have an adverse effect on their mental health.

Marcus Roberts is co-editor of Demography Is Destiny, MercatorNet's blog on population issues.