Does loneliness cause poor health or vice versa? A longitudinal analysis across European countries

Previous research has tended to focus on the association between loneliness and health individually, rather than exploring their reciprocal dynamics. This study examined the bidirectional effects between loneliness and several health outcomes among adults aged 50 and over, using data from the Survey on Health, Ageing and Retirement in Europe (SHARE). Structural equation modelling based on a cross-lagged panel strategy was employed to analyse the causal predominance of the effects between loneliness and chronic conditions, cognitive function, functional limitations and depressive symptoms. Except for chronic conditions, results revealed dynamic and bidirectional effects between loneliness and health outcomes. An asymmetrical pattern was found in the relationship between loneliness and chronic diseases, suggesting a unidirectional effect from chronic illness to loneliness. In contrast, loneliness was identified as a relevant longitudinal driver for worsening mental, cognitive and functional health, indicating that it contributes more directly to deterioration in these specific health domains than the reverse. These findings suggest that loneliness is a consequence as well as a driver of health deterioration in adult populations. By offering population-based evidence, this study underscores the need for multidimensional public health interventions and resource allocation strategies aimed at mitigating loneliness as a modifiable risk factor in ageing societies. Interventions such as social prescribing, community-based engagement programmes and psychosocial support may be key strategies to help break this negative cycle and promote healthy ageing.