Although loneliness affects a slate of health outcomes, its strongest effects appear to target mental health and overall well-being, according to a comprehensive review and meta-analysis published online in Psychiatry Research.
“From a public health perspective, the adequate training of healthcare providers to perceive, detect, and respond to loneliness among patients should be prioritized,” researchers advised. “Currently, loneliness is not systematically assessed and treated by clinicians; however, due to its potential adverse effects on health outcomes, the assessment and treatment of loneliness should be integrated into routine clinical care.”
To evaluate the comparative effects of loneliness on a handful of broadly defined yet distinct health outcomes (mental health, general health, well-being, physical health, sleep, and cognition), researchers reviewed and analyzed 114 studies that looked at associations between loneliness and one or more health outcomes.
The main analysis showed medium-to-large effects of loneliness on all health outcomes, with the largest effects on mental health and overall well-being. Random effects meta-analyses revealed the followed pooled effects of loneliness on specific mental health outcomes: -0.497 for depression, -0.417 for anxiety, -0.516 for suicidality, -0.489 for general mental health, and -0.476 for well-being. In contrast, effects on sleep and cognition were much smaller, with pooled correlations of -0.293 and -0.189, respectively.
The breadth of studies investigating the association between loneliness and mental health, compared with other health outcomes, may have confounded the meta-analysis results, researchers noted. Nevertheless, findings are in line with previous meta-analyses that found significant effects of loneliness on mental health outcomes, they wrote.
“Future research should better characterize the risk and protective factors associated with loneliness,” investigators concluded, “as well as identifying effective therapeutic options.”