This paper identifies the fact that extensive research has documented the importance of social relationships for promoting mental health and protecting against the development and progression of physical illness and disease. Integrative reviews of the literature provide consistent evidence that social relationships – both quantity and quality – are a major contributing factor in lowering broad-based morbidity and mortality. By contrast, loneliness has been linked to diminished longevity particularly among older individuals in whom declining economic resources, illness, widowhood, and impaired mobility may result in increased risk for social isolation.
At older ages, loneliness is also a major risk factor for broad-based morbidity (both psychological and physical). Growing evidence indicates that loneliness is associated with a wide range of health outcomes in later life, even after adjusting for objective indices of social isolation. For example, independent of objective features of social relationships (e.g., living arrangement, number and frequency of contacts, presence and propinquity of caregivers), loneliness has been associated with impaired daytime functioning, reduced physical activity, lower subjective well-being, and poorer physical health. Moreover, loneliness has been shown to prospectively predict increased depressive symptomatology, impaired cognitive performance, dementia progression, significant likelihood of nursing home admission, and multiple disease outcomes (e.g., hypertension, heart disease, and stroke in older persons) .
Published online 2015 Nov 6. doi: 10.1159/000441651