Loneliness and the onset of new mental health problems in the general population.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of non-randomized longitudinal cohort studies.
PubMed 35583561 · doi:10.1007/s00127-022-02261-7
What was done
Authors conducted a systematic review and meta-analysis of longitudinal studies published up to August 2021 across six electronic databases and unpublished sources. The review examined the relationship between baseline loneliness and the subsequent new onset of mental health problems (depression, anxiety, self-harm) in general population samples. A meta-analysis was performed across 8 independent cohorts, supplemented by narrative synthesis across 32 included studies.
What was found
The narrative synthesis indicated that most included studies found baseline loneliness was associated with subsequent new onset of depression, with a smaller number of studies reporting positive associations with anxiety and self-harm. In the meta-analysis of 8 independent cohorts, adults who were often lonely had a pooled adjusted odds ratio of 2.33 (95% CI 1.62–3.34) for developing new-onset depression compared to those who were not often lonely.
Why it matters
This review establishes a prospective, longitudinal link showing that loneliness independently precedes the onset of clinical depression, indicating loneliness is a distinct public mental health risk factor rather than merely a symptom of existing illness.
Limits
The findings are observational and cannot establish causality. Significant heterogeneity was present across meta-analyzed cohorts. The vast majority of the literature focused almost exclusively on depression, providing limited data for anxiety, psychosis, or self-harm, and the abstract notes a lack of evidence across diverse demographic and age groups.
Cited by
- supports Social isolation is a trigger for depression.