If we use the British Crime Survey estimates of the number of users, we can get a rough idea of the annual risk of using different drugs in micromorts (that is, the chance in a million of dying).
Averaging over the period between 2003 and 2007, cocaine and crack cocaine were involved in 169 deaths per year, and so an estimated 793,000 users were each exposed to an average of 213 micromorts a year, or around four a week. Ecstasy’s 541,000 users experienced around 91 micromorts a year each: the 2003 market for Ecstasy has been estimated as 4.6 tonnes, corresponding to around 14,000,000 tablets, or an average of around 26 per user. This translates to around 3.5 micromorts per tablet.
Cannabis rarely directly leads to death, but its estimated 2,800,000 users suffered an average of 16 associated deaths per year, which is 6 micromorts a year. The average of 766 heroin-related deaths a year comes out as 19,700 micromorts per year – 54 a day – but this will be an underestimate.
But there are many other harmful effects apart from death: for example, it’s been estimated that smokers of cannabis are about 2.6 times more likely to have a psychotic-like experience than non-smokers. Apart from the risks of dependence and withdrawal, heroin users may get HIV or hepatitis from non-sterile needles, or abscesses and poisoning with contaminants. Not forgetting the standard effect of opiates on chronic constipation.
So how can we compare the harms of different drugs, including legal ones such as alcohol and tobacco? A study published in 2010 looked at harms to users, such as mortality, damage to physical and mental health, dependence, and loss of resources and relationships, as well as harms to society, such as injury of others, crime, environmental damage, family adversities, international damage, economic cost and effects on the community. Each drug was scored on each dimension, the different harms weighted according to their judged importance and a total harm score calculated.
The resulting ranking put alcohol at the top with 72, then heroin and crack cocaine at 55 and 54, tobacco was 6th at 26, and ecstasy almost at the bottom of the list with nine, in spite of it being a Class A drug in the UK. This was controversial, with one national UK tabloid newspaper proclaiming that the main author, Professor David Nutt, was a ‘dangerous man’.
Even more controversial than comparing illegal and legal drugs, is to compare illegal drugs with ‘wholesome’ activities. Again it was Nutt, then head of the Advisory Council for the Misuse of Drugs (ACMD), who wrote a paper comparing ecstasy with ‘equasy’, the addiction to horse-riding, claiming that these were both voluntary leisure activities of young people, and of comparable dangers. He did not stay as head of the ACMD for much longer.