The risk for psychiatric disorders in offspring from thrombosis-prone pedigrees in Sweden: a nationwide family study

Background: Psychiatric disorders have been associated with venous thromboembolism (VTE). However, to our knowledge, no nationwide study has examined the familial association between VTE and psychiatric disorders. Objectives: We took a pedigree-based approach and examined the risk of psychiatric disorders in offspring from extended pedigrees according to the densities of VTE in pedigrees. Methods: This was a Swedish national family study. We identified a total of 482,184 Swedish pedigrees from the Swedish Multigeneration Register containing a mean of 14.2 parents, aunts/uncles, grandparents, and cousins of a core full-sibship that we termed the pedigree offspring (n = 751,060). We then derived 8 empirical classes of these pedigrees based on the density of cases of VTE. The risk was determined in offspring for psychiatric disorders as a function of VTE density in their pedigrees. Diagnoses of VTE and psychiatric disorders (F00-F69) were determined according to the International Classification of Diseases codes in Swedish registers. All results were Bonferroni corrected. Results: Higher VTE density, especially for females in pedigrees, was significantly but weakly associated in the offspring with a higher risk of psychiatric disorders. Moreover, VTE density in pedigrees was significantly associated in the offspring with substance abuse disorders, mood (affective) disorders, neurotic, stress-related, and somatoform disorders, behavioral syndromes associated with psychological disturbances and physical factors, personality disorders of adult personality and behavior, depression, and anxiety disorders. Conclusion: Offspring of pedigrees with a high density of VTE, especially for females, are slightly disadvantaged regarding several psychiatric disorders. VTE shares familial susceptibility, albeit weak, with several psychiatric disorders.