California could become the first US state to legalise magic mushrooms, as early as next year if proposed legislation is passed. The move, known as a ballot measure in the US, was filed last week with the state Attorney General's office.

The measure would exempt 21-year-old adults from suffering penalties for possessing, selling, transporting, or cultivating psilocybins – the psychedelic compound found in some types of mushroom. The proposal was filed by Kevin Saunders, a former candidate for mayor in Marina, a city on California's central coast.

Californians have already voted to legalise recreational marijuana use in November 2016, via a measure called Proposition 64, passed by 56% voters across the state.

Saunders said using mushrooms helped him stopped his reliance on heroin 15 years ago. "I think we're seeing something that could literally heal our brothers and sisters," he told the Los Angeles Times. "We're talking about real cutting-edge stuff."

Saunders said he hopes voters will be mature and have a serious conversation about the use of mushrooms. "It's a natural progression from marijuana legalisation," he said. "I think that we are having an opportunity to lead the discussion."

Widespread debate

Saunders will need to collect 365,880 valid voter signatures to place the measure on a statewide ballot next year. But even then the measure is sure to provoke widespread debate among hardline and liberal drug campaigners.

The liberal Drug Policy Alliance told LA Weekly: "DPA agrees that no one should be arrested or incarcerated simply because they possess or use psilocybin or other drugs.

"However, there are many factors to consider when deciding whether to run or support a ballot measure in California, and DPA does not yet have a position on this measure at this time."

Psilocybin is considered a Schedule I drug by the California Controlled Substances Act and the US Drug Enforcement Agency (DEA). Drugs in this ranking have no accepted medical use and a high potential for dependence and abuse, according to the DEA. Heroin, LSD, and marijuana are in the same category.

However, a New York University study and a Johns Hopkins University research paper published late last year found that psilocybin helped ease anxiety and depression for some cancer patients. In the UK, magic mushrooms are illegal and classified as a Class A drug.