Understanding the Role of Loneliness in the Relationships Between Post-Traumatic Stress Symptoms and Both Anxiety and Depressive Symptoms Among University Students: A Mediation Analysis

Background/Objectives: Both traumatic and stressful events, including major life changes, may contribute to post-traumatic stress symptoms (PTS), often associated with anxiety and depression. Feelings of loneliness may influence these relationships, whilst social support seems to mitigate the effects of stressful events on mental health. Our study thus aimed to evaluate the mediating role of loneliness in the relationships between PTS and both anxiety and depressive symptoms among university students. Methods: The data were from the CAMPUS study (0058642/21; FHMS 20-21 157), a survey on university students’ mental health in Italy and the UK. Using a logit model, mediation analyses were carried out to test whether the relationships between PTS and both anxiety and depressive symptoms might be mediated by loneliness. A path analysis was then performed to jointly test the associations between the Impact of Event Scale—Revised (IES-R)’s subscales and clinical domains. Results: Positive associations were found between PTS and both anxiety (p < 0.001) and depressive symptoms (p < 0.001). However, loneliness mediated approximately 22% of the effect of the PTS on anxiety symptoms (indirect effect: 1.04, 95% CI: 0.59; 1.48, p < 0.001) and approximately 33% of the effect of the PTS on depressive symptoms (indirect effect: 1.81, 95% CI: 1.22; 2.39, p < 0.001). Furthermore, the path analysis indicated associations between the IES-R’s hyperarousal subscale and both anxiety (coeff.: 0.34, p < 0.001) and depressive symptoms (coeff.: 0.27, p < 0.001). Conclusions: Along with the associations between PTS and both anxiety and depressive symptoms, our findings highlight the key role of loneliness in both these associations. Targeted interventions to reduce loneliness, especially for students exposed to traumatic events, may ultimately improve their mental health.