Although often associated with ageing, disability is becoming increasingly prevalent among young adults. While disability can pose a substantial psychological burden for young adults on critical pathways to establish the foundations for their future, the mental health risks faced by this population remain underexplored.

This study aimed to (1) assess the association between disability – including its presence, severity and type – and the risk of depressive and anxiety disorders, and (2) examine whether this association varies across sociodemographic factors, health behaviours and comorbidities in a young adult population.

We conducted a population-based cohort study using linked data from the National Disability Registry and the National Health Insurance Database of South Korea. A total of 6,058,290 individuals aged 20–39 years who underwent health check-ups between 2009 and 2012 were followed through 2022. Cox proportional hazards models were used to estimate adjusted hazard ratios (aHRs) for depressive and anxiety disorders.

Individuals with disabilities had significantly higher risks of depressive (aHR: 1.58, 95% CI: 1.55–1.60) and anxiety disorders (aHR: 1.50, 95% CI: 1.42–1.59). Increased risks were consistently observed across various disability types with the highest risk observed for mental health-related disabilities in depression (aHR: 4.98, 95% CI 4.62–5.37) and epilepsy-related disabilities in anxiety disorders (aHR: 12.05, 95% CI 8.73–16.63). Subgroup analyses revealed stronger associations among individuals in their 20s, low-income groups, non-smokers and those abstaining from alcohol, compared to their respective counterparts.

Young adults with disabilities, a population that has been relatively overlooked in policy discussions, warrant greater policy attention in relation to their mental health.

Loneliness is a global public health concern that has been widely associated with a variety of mental health impairments. Two dimensions of loneliness have been differentiated, that is, social loneliness (the perceived absence or inadequacy of a broader social network) and emotional loneliness (the perceived absence of a close, intimate relationship or emotional support from a significant person). The present study aimed to test the hypothesis that both dimensions of loneliness are differentially associated with mental health outcomes.

Altogether, 3275 individuals (aged 45.2 ± 15.7 years, 47.9% men), enrolled from the general population, were assessed at two waves spanning 6 to 7 months. Social and emotional loneliness were quantified using the 11-item De Jong Gierveld Loneliness Scale. Social isolation was assessed with the six-item Lubben Social Network Scale, depressive symptoms with the Patient Health Questionnaire-9, generalised anxiety with the Generalised Anxiety Disorder-7, social anxiety with the Social Interaction Anxiety Scale, and paranoid ideation with the Revised Green et al. Paranoid Thoughts Scale. The data were analysed using a cross-lagged panel network model. Covariates included age, gender, education, employment status, place of residence, monthly income, the history of psychiatric treatment and substance use.

Both dimensions of loneliness were bidirectionally associated and were found to have the highest overall weight of outcoming network connections. Emotional loneliness was bidirectionally and positively associated with all measures of mental health. In turn, social loneliness predicted higher levels of social anxiety but was not associated with other mental health outcomes. It was bidirectionally associated with social isolation.

The findings imply the relevance of differentiating social and emotional dimensions of loneliness in the assessment of its underlying mechanisms and consequences for mental health. Emotional loneliness might show a greater importance in the development of psychopathological symptoms compared to its social dimension.