In brief:

People in more equal societies are less likely to use use illegal drugs.

In more detail:

No one doubts the damage done by widespread drug addiction, both to its victims and in funding organised crime.

The World Drug Report 2007, compiled by the United Nations Office on Drugs & Crime, contains the results of sample surveys on the prevalence of the use of opiates, cocaine, cannabis, ecstasy and amphetamines. We combined these in one index, giving them equal weights, and found a strong tendency for drug abuse to be more common in more unequal countries.

Among the 50 states of the USA drug addiction and deaths from drug overdoses are related to inequality. Again we found that the more unequal states had higher death rates.

Click Image to enlarge

Notes on statistical sources and methods

For more information

Wilkinson RG, Pickett KE. The problems of relative deprivation: why some societies do better than others. Social Science and Medicine 2007, doi:10.1016/j.socscimed.2007.05.041.

UN Office on Drugs & Crime, World Drug Report 2007.

Wilkinson RG, Pickett KE. The Spirit Level. Penguin. 2009. Buy the book from Amazon.