FUNDING AND DISCLOSURE The study was supported by a Medical Research Council grant to Professor Catherine Harmer. Dr Martina Di Simplicio was supported by the doctoral research program in Applied Neurosciences of the University of Siena, Italy. Sonia Doallo was supported by a postdoctoral contract from the Isidro Parga Pondal program (Xunta de Galicia, Spain). Professor Catherine Harmer is a company director of Oxford Psychologists and has received consultancy or speaker fees from P1vital, Servier, Lundbeck, and Eli-Lilly. Professor Catherine Harmer is on the advisory panel and holds shares in P1vital. The other authors declare no conflict of interest.