According to the Office for National Statistics, the ONS, in England and Wales deaths involving heroin and morphine have more than double since 2012. The ONS say this is partially driven by a rise in heroin purity and availability over the last three years. Age, they say, is also a factor because heroin users are getting older and they often have other conditions, such as lung disease and hepatitis that make them particularly vulnerable. But are these the only reasons? John Middleton, president of the UK's faculty of public health, in an editorial in this week's British Medical Journal, thinks that a change in policy towards the management of addiction, a few years back, might be more to blame. Chris asked him first what he thought of the ONS' own conclusions...