These figures are good news.
At least things are not getting worse. That is reassuring. A decline in the number of addicts is what I would have expected thanks to the expansion of treatment. The treatments work – this is really compelling.
It represents a challenge to the view being propagated by the Conservatives, who are opposed to maintenance therapy – keeping addicts on methadone. They don't want maintenance therapy – they want a cure.
The reason this reduces the number of addicts is that as soon as you take away their prescribed drug – methadone – they will have to find an alternative. Most will get it illegally and to raise the money to pay for it will commit crime and sell the drug to other users.
Getting people into treatment reduces the need for addicts to make other people addicts and thus reduces the addict population on methadone. We don't have effective treatments for stimulant drugs such as cocaine and amphetamine. However, it is clear a lot of people switched from cocaine and ecstasy to mephedrone – because they knew what they were getting. The benefit of mephedrone is that it is much less toxic than cocaine.
The best way to get addicts off drugs is to find treatments that stabilise them. But almost no research is being done because of the Government's simplistic view addiction is not an illness. We need to change this view and increase investment.
Professor David Nutt is based at Imperial College, London