Loneliness has become a major public health issue of the recent decades due to its severe impact on health and mortality. Little is known about the relation between loneliness and social anxiety. This study aimed (1) to explore levels of loneliness and social anxiety in the general population, and (2) to assess whether and how loneliness affects symptoms of social anxiety and vice versa over a period of five years.

The study combined data from the baseline assessment and the five-year follow-up of the population-based Gutenberg Health Study. Data of N = 15 010 participants at baseline (Mage = 55.01, s.d.age = 11.10) were analyzed. Multiple regression analyses with loneliness and symptoms of social anxiety at follow-up including sociodemographic, physical illnesses, and mental health indicators at baseline were used to test relevant covariates. Effects of loneliness on symptoms of social anxiety over five years and vice versa were analyzed by autoregressive cross-lagged structural equation models.

At baseline, 1076 participants (7.41%) showed symptoms of social anxiety and 1537 (10.48%) participants reported feelings of loneliness. Controlling for relevant covariates, symptoms of social anxiety had a small significant effect on loneliness five years later (standardized estimate of 0.164, p < 0.001). Vice versa, there was no significant effect of loneliness on symptoms of social anxiety taking relevant covariates into account.

Findings provided evidence that symptoms of social anxiety are predictive for loneliness. Thus, prevention and intervention efforts for loneliness need to address symptoms of social anxiety.

Intellectual disability (ID) has been linked to substance use-related problems (SUP). However, previous research is limited by the small sample sizes, lack of general population comparison and have not accounted for familial confoundings. The role of other psychiatric comorbidities also remains unknown.

To examine the risk of SUP in individuals with mild-ID and assess whether the associations depend on other psychiatric comorbidities, controlling for potential familial confounding.

Population-based cohort study of individuals born in Sweden 1973-2003. We identified 19,078 individuals with mild-ID, 953,900 reference individuals from the general population, and 20,722 full-siblings of individuals with mild-ID. Conditional logistic regression models were used to compare individuals with mild-ID to the general population and their full-siblings regarding the risk of SUP, including alcohol and substance use disorders, alcohol and substance-related somatic diseases, substance-related crime, and substance-related death. Analyses were repeated stratified by the presence of psychiatric comorbidities.

Individuals with mild-ID had increased risks of any SUP (adjusted OR [95%CI]: 1.41 [1.35, 1.47]), compared to the general population, including alcohol-related somatic diseases (3.27 [1.92, 5.59]), alcohol (2.05 [1.91, 2.22]) and drug-use disorder (1.79 [1.69, 1.91]), and alcohol (1.36 [1.19, 1.49]) and drug-related crime (1.27 [1.19, 1.36]). The risk of SUP for individuals with mild ID was particularly elevated with comorbid mood (3.74 [3.47, 4.04]), anxiety (3.30 [3.09, 3.53]) and attention-deficit/hyperactivity disorders (2.61 [2.44, 2.80]). Increased risk of SUP remained significant when controlling for familial confounding.

Individuals with mild-ID, especially those with other psychiatric comorbidities, are at increased risks of SUP.

No significant relationships.