Submitted for Publication: August 7, 2012; final revision received November 29, 2012; accepted November 30, 2012.
Published Online: June 12, 2013. doi:10.1001/jamapsychiatry.2013.193.
Study concept and design: Sutin, Terracciano, and Zonderman.
Acquisition of data: Ferrucci and Zonderman.
Analysis and interpretation of data: Sutin, Terracciano, Milaneschi, and An.
Drafting of the manuscript: Sutin and An.
Critical revision of the manuscript for important intellectual content: Terracciano, Milaneschi, An, Ferrucci, and Zonderman.
Statistical analysis: Sutin, Terracciano, Milaneschi, An, and Zonderman.
Administrative, technical, and material support: An.
Study supervision: Ferrucci and Zonderman.
Conflict of Interest Disclosures: None reported.
Funding/Support: This research was supported in part by the Intramural Research Program of the National Institute on Aging, National Institutes of Health.
Role of the Sponsor: The funder had no role in the design and conduct of the study; in the collection, analysis, and interpretation of the data; or in the preparation or review of the manuscript or the decision to submit it for publication.