The illegal drugs with legal medical uses

Ketamine can be prescribed by a doctor but is widely used as an illegal party drug

A study of more than 100 people suggests ketamine could be used to help treat people suffering with depression.

Although it can be medically prescribed as an anaesthetic, it's widely used as an illegal party drug.

This kind of unregulated use can lead to harmful side effects, including serious liver and kidney damage.

But if it could be used to treat depression in the future, what other illegal drugs would it join for legitimate use as medical treatments?

BBC Advice has help and information if you are worried about drug use, as well as explaining the risks and penalties of illegal drug-taking.

Sultan Sid Dajani is a pharmacist in Bishopstoke near Southampton, who also speaks on behalf of the Royal Pharmaceutical Society.

He talked Newsbeat through some of the drugs which have perfectly legal uses, but can also be abused and used illegally.

Codeine

This painkiller is available without a prescription to buy over the counter in chemists and pharmacies.

It's an ingredient often used in things like co-codamol.

It is often used on its own as a suppressant to treat dry coughs but is very addictive and can be used as an opiate.

Cannabis

Now available in the UK on prescription, the medical equivalent of cannabis is Sativex.

It's an oral spray, used underneath the tongue. It's able to help with pain relief but, because of the design, isn't able to be used by people trying to get high.

Cannabis is now medically available on prescription in the UK

Nitrous oxide

Used by medical professionals like dentists, nitrous oxide can offer pain relief. But it can be abused and used illegally and is often called "laughing gas".

Dextromethorphan

With a street name of DXM this drug is medically known as a deliriant. In small doses it can be used to treat dry coughs.

But, if abused, it can lead to a feeling of losing control of your body, shortness of breath and dizziness.

Cocaine

This illegal drug is rated as class A. Being caught possessing it can carry a maximum prison sentence of up to seven years.

In the medical world it is still used in low doses as an anaesthetic by dentists.

Cocaine fuels a multi-billion pound criminal industry that stretches around the world

Pseudoephedrine

This is used as a nasal decongestant but, in large doses, can be used to make methamphetamine - the drug more commonly known as crystal meth, of Breaking Bad fame.

Heroin

This can have a devastating effects on individuals, families and communities when used illegally, experts say.

Another class A drug there are huge physical and legal consequences for people who abuse it.

Legally, it's used as diamorphine by medical professionals administering palliative, or end of life care.

They're not worried about its highly addictive nature, prioritising instead how it can help ease the pain of people who may only have a few days or weeks left to live.

Anabolic steroids

Used correctly, they can be prescribed to elderly people to help put on weight.

They can be abused by people who want to bulk up at the gym.

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