US Leads World In Substance Use

An international team of top-notch researchers has analyzed the substance use results from the World Health Organization's Mental Health Surveys. According to the published findings, the United States leads the world in drug use. The study also shows that harsher drug policies do not lead to lower rates of use.

The scientific journal PLoS Medicine published the research article "Toward a Global View of Alcohol, Tobacco, Cannabis, and Cocaine Use: Findings from the WHO World Mental Health Surveys" on July 1, 2008. As noted in the Editor's Summary:

"Data on drug use were available from 54,069 survey participants in 17 countries. The 17 countries were determined by the availability of collaborators and on funding for the survey. Trained lay interviewers carried out face-to-face interviews (except in France where the interviews were done over the telephone) using a standardized, structured diagnostic interview for psychiatric conditions. Participants were asked if they had ever used (a) alcohol, (b) tobacco (cigarettes, cigars or pipes), (c) cannabis (marijuana, hashish), or (d) cocaine. If they had used any of these drugs, they were asked about the age they started using each type of drug. The age of first tobacco smoking was not assessed in New Zealand, Japan, France, Germany, Belgium, The Netherlands, Italy, or Spain. The interviewers also recorded the participants' sex, age, years of education, marital status, employment, and household income.

"The researchers found that in the Americas, Europe, Japan, and New Zealand, alcohol had been used by the vast majority of survey participants, compared to smaller proportions in the Middle East, Africa, and China. The global distribution of drug use is unevenly distributed with the US having the highest levels of both legal and illegal drug use among all countries surveyed. There are differences in both legal and illegal drug use among different socioeconomic groups. For example, males were more likely than females to have used all drug types; younger adults were more likely than older adults to have used all drugs examined; and higher income was related to drug use of all kinds. Marital status was found to be linked only to illegal drug use—the use of cocaine and cannabis is more likely in people who have never been married or were previously married. Drug use does not appear to be related to drug policy, as countries with more stringent policies (e.g., the US) did not have lower levels of illegal drug use than countries with more liberal policies (e.g., The Netherlands)."

The researchers themselves concluded:

"Globally, drug use is not distributed evenly. In general, the US had among the highest levels of use of all drugs. Much lower levels were observed in lower income countries in Africa and the Middle East, and lower levels of use were reported in the Asian locales covered.

"These variations cannot be regarded as static: there was greater drug involvement among younger than older adults in all countries, suggesting that drug use has and may continue to change over historical time. Interestingly, there was also evidence to suggest that male-female differences in risk of initiating drug use may be changing in more recent birth cohorts. This change was a consistent finding across countries, suggesting that a general shift may be occurring with respect to the traditional sex differences so often documented with drug use.

"Consistent trends were also documented with respect to the period of risk for initiation of drug use. In most countries, the period of risk for initiation of use was heavily concentrated in the period from the mid to late teenage years; there was a slightly older and more extended period of risk for illegal drugs compared to legal drugs. Analyses of possible intercohort differences in risk of initiation suggested not only that the levels of illegal drug use were higher, but also that in more recent cohorts, the period of risk was extending further into adulthood. This extension of the period of risk has implications for drug use prevention efforts, which often focus upon adolescents and do not actively target young adults. Clearly, for illegal drugs, there continues to be a window of risk of initiation of illegal drug use that persists well beyond that of most commonly targeted ages.

"Legal and illegal use of drugs was most strongly associated with age, sex, and income. Higher income was associated with a greater likelihood of drug use for all drug types examined, which is perhaps not surprising given that drug use requires disposable income. Relationship status was linked to illegal (but not legal) drug use: both cocaine and cannabis use were more likely among persons who had never been married or previously been married. These associations remained statistically robust after adjustment for age, sex, and the other variables considered here. These associations are consistent with previous research in the developed countries, which has linked illegal drug use with an individual's marital status.

"The use of drugs seems to be a feature of more affluent countries. The US, which has been driving much of the world's drug research and drug policy agenda, stands out with higher levels of use of alcohol, cocaine, and cannabis, despite punitive illegal drug policies, as well as (in many US states), a higher minimum legal alcohol drinking age than many comparable developed countries. The Netherlands, with a less criminally punitive approach to cannabis use than the US, has experienced lower levels of use, particularly among younger adults. Clearly, by itself, a punitive policy towards possession and use accounts for limited variation in nation-level rates of illegal drug use."

A copy of the article can also be found in the CSDP research archive.