School of Psychology and Neuroscience, University of Glasgow, Glasgow, G12 8QQ, UK

William Stewart, Shannon Gilchrist & Emma R. Russell

Department of Neuropathology, Queen Elizabeth University Hospital, 1345 Govan Rd, Glasgow, G51 4TF, UK

William Stewart

Department of Neuropathology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia

Michael E. Buckland, Andrew J. Affleck & Catherine M. Suter

School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia

Michael E. Buckland, Andrew J. Affleck & Catherine M. Suter

Alzheimer’s Disease Research Center and Chronic Traumatic Encephalopathy Center, Chobanian and Avedisian School of Medicine, Boston University, Boston, MA, 02118, USA

Bobak Abdolmohammadi, Victor E. Alvarez, Bertrand R. Huber, Christopher J. Nowinski, Thor D. Stein & Ann C. McKee

US Department of Veteran Affairs, Veterans Affairs (VA) Boston Healthcare System, Boston, MA, 02130, USA

Victor E. Alvarez, Bertrand R. Huber, Thor D. Stein & Ann C. McKee

Department of Neurology, Chobanian and Avedisian School of Medicine, Boston University, Boston, MA, 02118, USA

Victor E. Alvarez, Bertrand R. Huber & Ann C. McKee

Department of Pathology and Laboratory Medicine, Chobanian and Avedisian School of Medicine, Boston University, Boston, MA, 02118, USA

Victor E. Alvarez, Thor D. Stein & Ann C. McKee

US Department of Veteran Affairs, VA Bedford Healthcare System, Bedford, MA, 01730, USA

Bertrand R. Huber, Thor D. Stein & Ann C. McKee

National Center for PTSD, VA Boston Healthcare, Boston, MA, 02130, USA

Bertrand R. Huber & Ann C. McKee

Translational Neuropathology Research Laboratory, University of Pennsylvania, Philadelphia, PA, 19104, USA

Edward B. Lee

School of Health and Wellbeing, University of Glasgow, Glasgow, G12 8QQ, UK

Donald M. Lyall

Concussion Legacy Foundation, Boston, MA, 02115, USA

Christopher J. Nowinski

Department of Biostatistics, Boston University School of Public Health, Boston, MA, 02118, USA

Ann C. McKee

WS, EBL, AJA, CMS, ACM, TS, BRH, VA, and MEB conducted the original pathology assessments, collated clinical data, and generated the original observations at each site; DML, EM, and WS analyzed the collated datasets; WS provided a first draft of the manuscript and collated comments into a final submission draft; all other authors provided edits and comments on manuscript drafts.