Billy Caldwell, from Castlederg in County Tyrone, has turned 21, a milestone his mother Charlotte once feared he would not reach. Caldwell has a severe form of epilepsy that previously caused between 300 and 800 seizures a day.

His mother said pharmaceutical treatments had failed to control the seizures. She sought cannabis-based medicine in North America, and Billy was eventually prescribed a cannabis-derived treatment that stopped the seizures. He has now been three years without a seizure.

The family's legal battle became prominent in 2018 when cannabis oil brought from Canada was seized at Heathrow airport. Later that year, UK law changed to allow specialist doctors to prescribe cannabis-derived medicines in certain circumstances.

Billy receives his medicine through the NHS, which his mother said the family is fortunate to have. But she said access to medical cannabis remains a major problem for many patients who cannot afford private treatment. Some chronically ill people face monthly costs of hundreds of pounds, she said.

Caldwell said prescription cannabis is not a cure-all, and that like other medicines it works for some people and not for others. She also described improvements in Billy's balance, walking, and social interaction. He can now climb steps and engages with visitors in a way he did not before.

Billy still requires round-the-clock care, but his mother said the atmosphere at home has changed from years of emergency medication and constant fear. She said she no longer fears going to sleep at night.