Obsessive-compulsive disorder, tics and anxiety in 6-year-old twins

Research output: Contribution to journalArticle


Background. Previous reports of genetic influences on obsessive–compulsive disorder (OCD) symptoms have suggested moderate heritability. Family history studies of co-morbidity have found
familial aggregation with tics, especially for early-onset OCD, and familial aggregation with anxiety disorders. Method. Heritability of OCD and familial aggregation of OCD, tics and anxiety disorders were
investigated in a community sample of 6-year-old twins using a two-phase design in which 4662 twin pairs were sampled and 854 pairs were assessed in the second phase by maternal-informant diagnostic interview using DSM-IV criteria. Results. In the multivariate model combined additive genetic and common environmental effects were estimated as 47% for sub-threshold OCD, and the model was unable to distinguish these sources of familial aggregation. There were strong familial aggregations between sub-threshold OCD and tics and between sub-threshold OCD and other anxiety disorders (80% and 97% respectively), although again specific sources could not be distinguished. Conclusions. The findings are consistent with the hypothesis of a tic-related early-onset OCD phenotype, but also with the hypothesis of an anxiety-related early-onset OCD phenotype.


  • Derek Bolton
  • Fruhling Rijsdijk
  • Thomas O'Connor
  • Sean Perrin
  • Thalia Eley
External organisations
  • King's College London
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Psychology
Original languageEnglish
Pages (from-to)39-48
JournalPsychological Medicine
Issue number1
Publication statusPublished - 2006
Publication categoryResearch
Externally publishedYes