What do adult neurologists need to know ahead of the likely licensing of Epidiolex for epilepsy in the UK in 2019? It is quite possible that cannabidiol, currently licensed in the USA for treating rare genetic epilepsies, may open the door for the widespread legalisation of recreational cannabis. Dr Rhys Thomas (Neurologist at the Institute of Neuroscience, Newcastle University, UK) tells fellow Practical Neurology Associate Editor Dr Tom Hughes why the arguments about who may benefit from cannabis-derived medicines have to be separate from the discussion about the legalisation of recreational cannabis. They also discuss the distinction between cannabidiol oils and the cannabidiol rigorously tested in clinical trials. Read the review on the Practical Neurology website - https://pn.bmj.com/content/early/2018/10/18/practneurol-2018-002058 - and on the journal's December 2018 issue.