A 12-month randomised double-blind controlled international multicentre trial comparing changes in cigarette consumption after switching to high or low nicotine strength e-cigarettes in smokers with Schizophrenia spectrum disorders. This will be a multicenter 12-months prospective trial utilizing a randomized double-blind 2-arm parallel switching design to compare effectiveness tolerability acceptability and pattern of use between high (JUUL 5% nicotine) and low nicotine strength devices (JUUL 1.5% nicotine) in adult smokers with schizophrenia spectrum disorders. The study will take place at 5 sites: 1 in the UK (London) and possibly 4 in Italy.