Soni, M., Orrell, M., Bandelow, S., Steptoe, A., Rafnsson, S., d'Orsi, E., Xavier, A., & Hogervorst, E. (in press). Physical activity pre- and post-dementia: English Longitudinal Study of Ageing. Aging and Mental Health, https://doi.org/10.1080/13607863.2017.1390731