Study concept and design: Weissberg, Milikovsky, Friedman.
Acquisition, analysis, or interpretation of data: Weissberg, Veksler, Kamintsky, Saar-Ashkenazy, Shelef.
Drafting of the manuscript: Weissberg, Veksler, Kamintsky, Saar-Ashkenazy, Milikovsky.
Critical revision of the manuscript for important intellectual content: Weissberg, Kamintsky, Shelef, Friedman.
Statistical analysis: Weissberg, Veksler, Kamintsky, Saar-Ashkenazy, Milikovsky.
Obtained funding: Friedman.
Administrative, technical, or material support: Kamintsky, Saar-Ashkenazy.
Study supervision: Shelef, Friedman.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study was supported by the European Union’s Seventh Framework Program (FP7/2007-2013; grant agreement 602102, EPITARGET, to Dr Friedman) and the Israel Science Foundation (grant 713/11 to Dr Friedman).
Role of the Funder/Sponsor: The funders 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 Negev Football (Black Swarm) team for their participation in this study and Hadar Shalev, MD, and Sharon Naparstek, MsC, of the Department of Psychiatry, Soroka University Medical Center, for their advice on the study design. They did not receive compensation for the contributions.