Author Contributions: Study concept and design: Russ, Hamer, and Batty. Acquisition of data: Hamer, Stamatakis, and Batty. Analysis and interpretation of data: Russ, Starr, and Batty. Drafting of the manuscript: Russ and Batty. Critical revision of the manuscript for important intellectual content: Russ, Hamer, and Stamatakis, Starr, and Batty. Statistical analysis: Russ and Batty. Obtained funding: Stamatakis and Batty. Study supervision: Hamer, Starr, and Batty.
Financial Disclosure: None reported.
Funding/Support: Dr Russ is supported by Alzheimer Scotland and he is employed in the NHS by the Scottish Dementia Clinical Research Network, which is funded by the Chief Scientist Office (part of the Scottish Government Health Directorates). Dr Russ and Starr are members of the Alzheimer Scotland Dementia Research Centre funded by Alzheimer Scotland. Drs Russ, Starr, and Batty are members of the University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology, part of the cross council Lifelong Health and Wellbeing Initiative (G0700704/84698). Funding from the BBSRC, EPSRC, ESRC, and MRC is gratefully acknowledged. GDB is a Wellcome Trust Fellow.