[Loneliness as health risk: a narrative review]

Loneliness is increasingly recognized as a significant health risk. This review provides an overview of current research on the impact of loneliness on mental and physical health. The findings indicate that loneliness is a significant risk factor of both mental and physical health. Previous reviews focusing on mental health effects reveal that loneliness is associated with the onset of depression, social anxiety, and cognitive decline. Furthermore, loneliness can impede recovery from mental disorders in general, which can be partly attributed to the bidirectional interplay between loneliness and mental health. Regarding physical health, consequences of loneliness have been mostly studied in relation to cardiovascular diseases. Loneliness predicts the onset of cardiovascular diseases and impedes recovery from them. Reviews also highlight that loneliness enhances the likelihood of suicidality and mortality. However, this article also points out the shortage of longitudinal studies, complicating the investigation into how loneliness causally affects future health problems. The health implications of loneliness outlined in this review, some of which are irreversible and can induce suffering and impairment, underscore the importance of interventions aimed at alleviating loneliness as a preventive strategy against both mental and physical illnesses.