1. From the Translational and Clinical Research Institute (R.D., G.R., C.A.H., P.C.D., S.J.C., M.F., S.L., J.-P.T., A.J.T.), Newcastle University, Biomedical Research Building, Campus for Ageing and Vitality; Nuclear Medicine Department (G.R., K.H., G.S.P., J.J.L.), Royal Victoria Infirmary, Newcastle Upon Tyne; University of Exeter Medical School (L.M.A.), St Luke's Campus, University of Exeter; and Department of Psychiatry (J.T.O.B.), University of Cambridge School of Clinical Medicine, United Kingdom.