We asked an expert what he thought of Theresa May's ban on legal highs

Theresa May’s ban on legal highs has been widely mocked as it could accidentally ban substances such as solvents and nutmeg due to its wording.

But there's another reason why it is not a good piece of legislation. The Global Drugs Survey 2015, released on Monday, showed for a fourth successive year that legal highs and novel psychoactive drugs usage is declining.

This means the bill targets what appears to be drugs with declining usage statistics, year on year.

While new legal highs are cheap, the survey explained that the decline owes to the fact that they are also mostly less “desirable” and riskier than traditional drugs.

As Dr Adam Winstock, the senior lecturer in psychiatry at King's College London who conducted the Global Drugs Survey, told i100.co.uk this is why legal highs were at their peak in 2009-10 with Mephedrone.

"There was lots of poor coke around and there was no MDMA, so all of a sudden NPSs (novel psychoactive drugs) offered good value for money and good bang for buck," he said. "I think that the other big result in this for me is although the government and the European Monitoring Centre for Drugs and Drug Addiction say that the fastest growing group of Psychoactive drugs being found are the synthetic and adenoid products, very few places use them. The prevalence of use in most countries was around one per cent. And the reason was they’re just not that nice."

Dr Winstock added that while he supported May's bill because it could reduce the use of drugs such as synthetic Cannabis he was not sure a ban would reduce harm.

And then I look at Nitrous Oxide and I think 'You know what, we’ve put out probably the biggest scare story on Nitrous Oxide ever and it’s exactly the sort of thing Theresa May could look at and say: ‘You see, this is why I think it should be banned,’ but for me, what it says is: ‘No, you don’t need this regulation to reduce harm’.

I think governments have a duty of care to protect their populations from harm, and traditionally governments have done that using drug laws.

Every time a new drug comes along that poses a threat, they ban it, and I think that’s stopping the government from looking at other ways of changing people’s behaviour to reduce risk. Because ultimately, people aren’t stupid and they don’t want to expose themselves to risk.

The Global Drugs Survey is released annually and surveyed over 100,000 people this year.

Read more:These are all the things Theresa May's legal highs bill could accidentally ban