Today's Home Office evidencce-based report concludes that tough drug enforcement does not decrease use of illegal drugs and one reviewer has remarked:
It is the most significant report on drugs the British government has published for 40 years.
Drugs policy is not my area of interest, but I noted the references to the long term reduction internationally in drug use. The same reviewer adds
No-one is entirely sure why the decline is happening, although it is thought it could be linked to the decreasing popularity of smoking. Cannabis makes up the lion's share of illicit drug use and some experts believe the drug has declined in popularity, like tobacco, because smoking itself is increasingly seen as unfashionable. As cannabis rates fall, they drag down general drug use rates.
Link to report, 59 pgs:https://www.gov.uk/government/upload...omparators.pdf

The cited review:http://www.politics.co.uk/blogs/2014...es-not-lower-d

The BBC:http://www.bbc.co.uk/news/uk-29824764

Now whether this report has any impact is unclear. Very few were in the House of Commons today for a debate, although several Conservatives spoke in favour of reform.