Date Published: May 1, 2019
Publisher: Public Library of Science
Author(s): Louis Jacob, Josep Maria Haro, Ai Koyanagi, Soraya Seedat.
Given the high prevalence of common mental disorders (CMDs) and individuals living alone in the United Kingdom, the goal of this study using English nationally representative data was to examine the association between living alone and CMDs, and to identify potential mediating factors of this association. The data were drawn from the 1993, 2000 and 2007 National Psychiatric Morbidity Surveys. CMDs were assessed using the Clinical Interview Schedule-Revised (CIS-R), a questionnaire focusing on past week neurotic symptoms. The presence of CMDs was defined as a CIS-R total score of 12 and above. Multivariable logistic regression and mediation analyses were conducted to analyze the association between living alone and CMDs, and to identify mediators in this association. The prevalence of CMDs was higher in individuals living alone than in those not living alone in all survey years. Multivariable analysis showed a positive association between living alone and CMDs in all survey years (1993: odds ratio [OR] = 1.69; 2000: OR = 1.63; and 2007: OR = 1.88). Overall, loneliness explained 84% of the living alone-CMD association. Living alone was positively associated with CMDs. Interventions addressing loneliness among individuals living alone may be particularly important for the mental wellbeing of this vulnerable population.
Globally, the lifetime prevalence of common mental disorders (CMDs) is around 30% . CMDs have a major impact on quality of life , physical illness  and mortality . For example, depressive disorders were the second and anxiety disorders the sixth leading causes of years lived with disability in the Global Burden of Disease 2010 study, respectively [5,6]. The effects of CMDs are not limited to the individual level, and these chronic conditions are associated with an important economic burden . Therefore, there is a need for a better understanding of the risk factors of CMDs in order to improve the prevention, management and treatment of these disorders.
Of the 20503 individuals from England aged 16–64 years, 8903 were from the 1993 survey, 6175 from the 2000 survey, and 5425 from the 2007 survey (Table 1). The prevalence of those living alone in the respective surveys were 8.8%, 9.8% and 10.7%. The corresponding figures for CMD were 14.1%, 16.3%, and 16.4%, respectively. Male sex, older age and unemployment were more frequent in participants living alone than in those not living alone, while the distribution of education was significantly different between the two groups. Details of the relationship status of the participants by year and living arrangement (alone or not) are shown in Table 2. The answer options for the survey conducted in 2000 were different from those of 1993 and 2007 but across all surveys, there were very few people who were married but living alone. The prevalence of CMDs was higher in individuals living alone than in those not living alone in all surveys (1993: 19.9% versus 13.6%; 2000: 23.2% versus 15.5%; and 2007: 24.7% versus 15.4%; Fig 1). The results of the multivariable logistic regression analysis are shown in Table 3. There was a positive association between living alone and CMDs in the 1993 (odds ratio [OR] = 1.69; 95% confidence interval [CI]: 1.44–2.00), 2000 (OR = 1.63; 95% CI: 1.37–1.93) and 2007 datasets (OR = 1.88; 95% CI: 1.57–2.26). This association remained significant in the stratified analyses except in people aged 60–64 years in 1993 (OR = 1.59; 95% CI: 0.99–2.55) and 2000 (OR = 1.30; 95% CI: 0.76–2.22). The non-significance among the older population may have been due to lack of statistical power as the proportion of individuals in this age group was small in the 1993 and 2000 surveys (i.e., <8%). No significant interactions were found for smoking status, alcohol dependence and drug use in the 2007 dataset. Table 4 displays the results of the mediation analysis using data from 7403 people aged ≥16 years from England. Overall, loneliness explained 84% of the living alone-CMD association and no other significant mediators explaining more than 20% of this association were identified. Source: http://doi.org/10.1371/journal.pone.0215182