Submitted for Publication: November 20, 2014; final revision received March 31, 2015; accepted April 3, 2015.
Published Online: June 17, 2015. doi:10.1001/jamapsychiatry.2015.0627.
Study concept and design: Mataix-Cols, Lichtenstein.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Mataix-Cols, Isomura.
Critical revision of the manuscript for important intellectual content: Pérez-Vigil, Chang, Rück, K. J. Larsson, Leckman, Serlachius, H. Larsson, Lichtenstein.
Statistical analysis: Isomura, Pérez-Vigil, Chang, Lichtenstein.
Obtained funding: Mataix-Cols, Lichtenstein.
Administrative, technical, or material support: Isomura, Rück, K. J. Larsson, Serlachius, Lichtenstein.
Study supervision: Mataix-Cols, H. Larsson, Lichtenstein.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study was supported by the Tourette Syndrome Association (Dr Mataix-Cols), grant 2012-1678 from the Swedish Council for Working Life and Social Research (Dr Lichtenstein), and grant 2011-2492 from the Swedish Research Council (Dr Lichtenstein).
Role of the Funder/Sponsor: The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and the decision to submit the manuscript for publication.