The association between loneliness and common mental disorders in adults with borderline intellectual impairment

Background: Loneliness is linked to a number of adverse health outcomes in the general population. There is a lack of evidence on the prevalence and impact of loneliness in people with borderline intellectual impairment.

Methods: Data from the 2014 Adult Psychiatric Morbidity Survey, a national survey of England, was analysed using Weights-adjusted regression analyses to compare the prevalence of loneliness and the association between loneliness and socio-demographic and clinical variables in people with borderline intellectual impairment and the general population.

Results: Data from 6877 participants were included. Ten percent (n = 671) of the sample had borderline intellectual impairment and their prevalence of loneliness was 24.5% compared to 18.4% in the general population. This difference was explained by exposure to social disadvantages. Associations were found in both groups between loneliness and being single, unemployed, low income, lower social support, feeling unsafe and discrimination in the past year. Loneliness was associated with lower wellbeing and higher rates of common mental disorders, suicidal thoughts and chronic physical disorders in both groups. Intellectual functioning moderated the relationship between loneliness and income (OR 1.82; 95%CI 1.06 to 3.11) and suicidal thoughts in the last week (OR 0.13; 95% CI 0.02 to 0.93).

Limitations: IQ was measured using the National Adult Reading Test (NART), which is only valid for English speakers and loneliness was measured using a single item.

Conclusion: Loneliness is more prevalent in people with borderline intellectual impairment. Interventions targeting social disadvantages (e.g. low income) may lead reduce loneliness and vulnerability to mental health problems.