Since the publication of this article , it has come to the attention of the authors that information for one of the authors was not included in the competing interests section. Craig Richie has declared potential competing interests with the following companies; Janssen, Eisai, Pfizer, Eli Lilly, Roche Diagnostics, Boeringher Ingleheim, Novartis, AC Immune, Ixico, Aridhia, Amgen, Berry Consultants, Lundbeck, Sanofi, Quintiles (IQVIA) and Takeda. The full competing interests section for this article can be found below. Declarations Competing interests Bob Barber has participated in an advisory panel for Novartis on one occasion and conducted a number of pharmaceutical sponsored commercial clinical trials in Alzheimer's disease (including Lilly, Roche and Janssen). He has a national role for NIHR NHS relating to commercial studies in dementia. Nick Fox has received research support from AVID/Lilly and has advised GSK, Lilly, Novartis and Roche; he serves on a data monitoring committee for Biogen-all payments for these activities are to UCL. Clive Holmes has attended advisory boards for Lilly pharmaceuticals. Martin Rossor serves on a safety monitoring committee for Servier and has advised Merck on patient registries. Tom Russ works within NHS Scotland with the Scottish Neuroprogressive and Dementia Network on commercial studies in dementia. Craig Richie is the co-coordinator and academic lead for the EPAD (European Prevention of Alzheimer's Dementia) Project which has numerous commercial partners in keeping with the mechanisms of the European Union's Innovative Medicine's Initiative. These companies are: Janssen, Eisai, Pfizer, Eli Lilly, Roche Diagnostics, Boeringher Ingleheim, Novartis, AC Immune, Ixico, Aridhia, Amgen, Berry Consultants, Lundbeck, Sanofi, Quintiles (IQVIA) and Takeda. Jeremy Issacs is a Principal Investigator on clinical trials, outside of the submitted work, sponsored by both Roche and Merck & Co, who supply funding to his employing organisation to conduct the study. The remaining co-authors declare that they have no competing interests. All authors have completed the ICJME declaration of conflicts of interest.