Loneliness as a predictor of outcomes in mental disorders among people who have experienced a mental health crisis: a 4-month prospective study

Background Loneliness has not until recently been a prominent focus in research on outcomes of mental illness. The aim of this study was to determine whether loneliness at baseline predicts poor outcomes at 4-month follow-up for individuals who have experienced mental health crises. The outcomes in this study included overall symptom severity, affective symptoms, self-rated recovery and health-related quality of life. Methods Our study reports a secondary analysis of data from a randomised controlled trial. The sample (n = 399) was taken from patients who received treatment from community crisis services. Respondents (n = 310) completed the follow-up measurement 4 months after baseline. Loneliness at baseline was assessed using an eight-item UCLA Loneliness Scale. The four mental health outcomes were measured at both baseline and follow-up. Two scales (or part thereof) assessed objective social isolation and neighbourhood social capital at baseline. Regression analyses were conducted to investigate longitudinal associations between loneliness at baseline and mental health outcomes at follow-up. Results Loneliness at baseline was associated with all four mental health outcomes at 4-month follow-up, adjusting for psychosocial, socio-demographic and clinical characteristics. A one-point higher loneliness score was associated with 0.74-point (95% CI 0.45, 1.02) and 0.34-point (95% CI 0.21, 0.47) increase in overall symptom severity score and affective symptoms score respectively, and with 1.08-point (95% CI -1.45, - 0.71) and 1.27-point (95% CI -1.79, - 0.75) decrease in self-rated recovery score and health-related quality of life score respectively. Loneliness was a better predictor of clinical outcomes than objective social isolation and social capital, even though the associations with clinical outcomes were reduced and no longer statistically significant following adjustment for their baseline values. A significant association with quality of life persisted after adjustment for its baseline score. Conclusions Greater loneliness at baseline predicted poorer health-related quality of life at follow-up. There were cross-sectional associations between loneliness and clinical outcomes, but their longitudinal relationship cannot be confirmed. Further research is needed to clearly establish their underpinning pathways. Reducing loneliness may be a promising target to improve recovery for mental health community crisis service users.