The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study - Di Forti, Marta; Quattrone, Diego; Freeman, Tom P; Tripoli, Giada; Gayer-Anderson, Charlotte; Quigley, Harriet; Rodriguez, Victoria; Jongsma, Hannah E; Ferraro, Laura; Cascia, Caterina La; Del-Ben, Cristina Marta (Lancet psychiatry, 2019)