IT was a story that probably made many people reconsider their attitude to cannabis, but now it seems the case of Billy Caldwell has changed the mind of the Home Secretary too. Speaking about his decision to allow medicinal cannabis to be made available on prescription, Sajid Javid said recent cases involving sick children such as Billy had made it clear to him that the current position was not satisfactory. And therefore, in a rare liberal move from the Home Office, he said the law should change.

Anyone who has followed Billy’s story will know what he and his mother Charlotte have been through. Billy, who is 13, suffers from a rare form of epilepsy and his mother said only medicinal cannabis helped control the seizures. He began using it in 2016 but in June his supply was confiscated at Heathrow. Mr Javid then intervened to provide a temporary licence allowing the boy to be treated with the oil and also ordered a review into the law. That review has now been completed and will lead to reform.

The details will now have to be worked out of course. For a start, what exactly is, or is not, a cannabis medicinal product will have to be carefully defined, and the exceptional clinical need that will justify its prescription will have to be clear so doctors and patients know where they stand. Once those details are confirmed, the law will also need to be regularly reviewed to ensure it is working as intended – and it is entirely fair for the Scottish Government to ask for the NHS in Scotland to be involved in the development of clinical guidelines and in making sure the products prescribed to patients are safe. This is a radical change in the law after all and it must not be rushed.

As Mr Javid emphasised when making his announcement, there is also a difference between helping patients with a clinical need – which is justified – and the legalisation of cannabis for recreational use. Obviously, cannabis is increasingly socially acceptable and at the softer end of the spectrum – although stronger strains have increasingly come on to the illegal market – but Scotland still has a notoriously difficult relationship with drugs. Any form of decriminalisation or legalisation would have to be combined with reform of mental health and support services and much better warning systems to identify those who are at risk from their use of drugs, legal or illegal.

In the meantime, though, the Home Office has made the right decision on medicinal cannabis. In the words of Charlotte Caldwell, this now means her son can live a normal life because of the simple ability to administer a couple of drops a day of an effective medication. It is also hopefully a sign that the UK Government is prepared to do what it should have been doing all along on drug policy: listen to the evidence.