Submitted for Publication: September 30, 2013; final revision received March 10, 2014; accepted April 16, 2014.
Published Online: July 30, 2014. doi:10.1001/jamapsychiatry.2014.994.
Study concept and design: Zavos, Freeman, McGuire, Plomin, Ronald.
Acquisition, analysis, or interpretation of data: Zavos, Freeman, Haworth, McGuire, Plomin, Cardno, Ronald.
Drafting of the manuscript: Zavos, Freeman, Ronald.
Critical revision of the manuscript for important intellectual content: Freeman, Haworth, McGuire, Plomin, Cardno, Ronald.
Administrative, technical, or material support: Haworth.
Statistical analysis: Zavos.
Obtained funding: Plomin, Ronald.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study was supported by Medical Research Council grants G1100559 (Dr Ronald), G0901245, and G0500079 (Dr Plomin); UK Medical Research Council Senior Clinical Fellowship G0902308 (Dr Freeman); and the British Academy (Dr Haworth).
Role of the 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 decision to submit the manuscript for publication.
Additional Contributions: We thank the participants of TEDS for making this research possible. Special thanks to Andrew McMillan, BA, BSc, Francesca Lewis, BA, Louise Webster, BA, Neil Harvey, BSc, and Rachel Ogden, BA, and to Peter McGuffin, MB, PhD, FRCP, FRCPsych, FMedSc, for help planning the study.