Heavy drinkers and users of illegal drugs downplay their relative levels of consumption, when comparing themselves to others, reveals research by the London School of Economics and Political Science (LSE) and South London and Maudsley NHS Foundation Trust.

Published in the journal Social Science and Medicine, the research1 shows that 68 per cent of respondents to the Global Drugs Survey (GDS) - the world's biggest drug survey2 - were drinking at hazardous or harmful levels3, yet the vast majority (83 per cent) felt they were drinking at low or average levels.

The same pattern was evident across a range of illegal drugs. Although frequent and/or heavier users were more likely to judge their use to be above average than moderate users they still tended to downplay their levels of use. For example, the survey showed that using cannabis every day or most days was fairly unusual yet a third or more of respondents who used cannabis this frequently considered their use to be average (33 per cent) or less than average (42 per cent).

For ecstasy and cocaine, more than half of even the heaviest users thought they were using at no more than average levels.

Dr Michael Shiner, an associate professor in LSE's Department of Social Policy and expert advisor to the Global Drugs Survey, said: "Given that drug use carries certain risks, whether this be to health, of getting caught or of damage to reputation, we shouldn't be surprised that some people downplay their levels of use as a way of managing their anxieties about what they're doing."

A considerable proportion of GDS respondents wanted to reduce their existing levels of consumption. Thirty six per cent wanted to drink less alcohol and 25 per cent wanted to reduce their use of illicit drugs - mainly cannabis and cocaine.

The desire to cut down was linked to respondents' actual and perceived levels of use. Heavier users, and those who saw themselves as such, were more likely to want to reduce their consumption than those who used less or thought they did.

Regardless of respondents actual drinking habits, those who thought they were drinking at a high rate compared to others were almost twice as likely to want to cut down as those who thought they were drinking at average levels. Similar effects were evident in relation to cannabis, ecstasy and cocaine.

Dr Adam Winstock, a Consultant Addiction Psychiatrist at Maudsley Hospital, and creator of the Global Drugs Survey said: "Whether drugs are classified as illegal or not, there is group of people who will continue to use them, so we need ways, other than the law, of changing behaviour. With this in mind we've created an app where people can confidentially input their use and it will give them a true picture of how their use compares to others. We hope that for some people this might provide the jolt they need to address their excessive alcohol or drug use. "

The Global Drug Survey has been used to develop Drinks-meter and Drugs-meter, web and smartphone self-assessment tools that provide personalised feedback to users about their levels of drinking / drug use and how they compare with others. The apps are available at:

In 2012 the Global Drugs survey was completed by 7719 respondents from the United Kingdom, who providing the basis for this analysis.

The 2016 survey will launch on 15 November this year.