For decades it was cast as a harmful gateway drug to a lifestyle of feckless criminality. But the last few months has brought a momentous shift in the official position on cannabis following pressure from families who have used it to treat conditions like epilepsy.

Home secretary Sajid Javid has announced a review of the drug’s medical benefits and said it will be available on prescription this autumn.

Javid’s about turn came following pressure from Charlotte Caldwell, whose 12-year-old son Billy has autism and a rare form of severe epilepsy that saw him endure up to 100 seizures a day.

Pressure was also brought to bear by Hannah Deacon, whose son Alfie Dingley, six, suffered 150 seizures a month.

Both parents were eventually given licences by the Home Office to use cannabis for their children’s seizures.

Autumn has now arrived, but the official Home Office position suggests it’s still too early for patients to go to their GPs pleading for cannabis.

The Home Office say they are continuing to work with the Advisory Council on the Misuse of Drugs (ACMD) on the legal changes designed to help patients with “an exceptional clinical need”.

But in the meantime an expert panel has been set up to review decisions made by doctors trying to prescribe cannabis for patients before the law changes.

Parents and adults struggling with autism say though the government’s rethink is welcome, the focus on “exceptional clinical need” is too narrow.