Abstract
OBJECTIVE: To estimate the association and familial coaggregation of childhood-onset type 1 diabetes with depression, anxiety, and stress-related disorders. RESEARCH DESIGN AND METHODS: This was a population-based cohort study with use of data from Swedish nationwide registers. A total of ∼3.5 million individuals born in Sweden 1973-2007 were linked to their biological parents, full siblings and half-siblings, and cousins. Cox models were used to estimate the association and familial coaggregation of type 1 diabetes with depression, anxiety, and stress-related disorders. RESULTS: Individuals diagnosed with childhood-onset type 1 diabetes (n = 20,005) were found to be at greater risks of all outcomes: any psychiatric diagnosis (adjusted hazard ratio [aHR] 1.66 [95% CI 1.59-1.72]) or specific diagnoses of depression (1.85 [1.76-1.94]), anxiety (1.41[1.33-1.50]), and stress-related disorders (1.75 [1.62-1.89]), as well as use of antidepressants or anxiolytics (1.30 [1.26-1.34]), compared with individuals without type 1 diabetes. Overall, relatives of individuals with type 1 diabetes were at elevated risks of developing these outcomes, with the highest risks seen in parents (aHRs 1.18-1.25), followed by full siblings (aHRs 1.05-1.20), and the magnitudes of risk estimates appear proportional to familial relatedness. CONCLUSIONS: These results support existing evidence that children and adolescents with type 1 diabetes are at greater risks of developing depression, anxiety, and stress-related disorders and indicate that shared familial factors might contribute to these elevated risks. Our findings highlight the need for psychological consulting for children and their families in diabetes care. Quantitative and molecular genetic studies are warranted to further understand the etiology of these psychiatric disorders in type 1 diabetes.