The world's most extensive study of the drug trade has just been published in the medical journal BMJ Open, providing the first "global snapshot" of four decades of the war on drugs. You can already guess the result. The war on drugs could not have been a bigger failure. To sum up their most important findings, the average purity of heroin and cocaine have increased, respectively, 60 percent and 11 percent between 1990 and 2007. Cannabis purity is up a whopping 161 percent over that same time. Not only are drugs way purer than ever, they're also way, way cheaper. Coke is on an 80 percent discount from 1990, heroin 81 percent, cannabis 86 percent. After a trillion dollars spent on the drug war, now is the greatest time in history to get high.

The new study only confirms what has been well-established for a decade at least, that trying to attack the drug supply is more or less pointless. The real question is demand, trying to mitigate its disastrous social consequences and treating the desire for drugs as a medical condition rather than as a moral failure.

But there's another question about demand that the research from BMJ Open poses. Why is there so much of it? No drug dealer ever worries about demand. Ever. The hunger for illegal drugs in America is assumed to be limitless. Why? One answer is that drugs feed a human despair that is equally limitless. And there is plenty of despair, no doubt. But the question becomes more complicated when you consider how many people are drugging themselves legally. In 2010 the CDC found that 48 percent of Americans used prescription drugs, 31 percent were taking two or more, and 11 percent were taking five or more. Two of the most common prescription drugs were stimulants, for adolescents, and anti-depressants, for middle-aged Americans.

Both the legal and illegal alteration of consciousness is at an all-time high. And it is quickly accelerating. One of the more interesting books published in the past year is Daniel Lieberman's . It is a fascinating study by the chair of the department of human evolutionary biology at Harvard of how our Paleolithic natures, set in a hypermodern reality, are failing to adjust. His conclusions on the future of the species are somewhat dark:

"We didn't evolve to be healthy, but instead we were selected to have as many offspring as possible under diverse, challenging conditions. As a consequence, we never evolved to make rational choices about what to eat or how to exercise in conditions of abundance and comfort. What's more, interactions between the bodies we inherited, the environments we create, and the decisions we sometimes make have set in motion an insidious feedback loop. We get sick from chronic diseases by doing what we evolved to do but under conditions for which our bodies are poorly adapted, and we then pass on those same conditions to our children, who also then get sick."

Our psychological reality is equally unadjusted to the world we live in. Cortisol levels — the stress hormone — evolved to increase during moments of crisis, like when a lion attacks. If you live in a city, your cortisol levels are constantly elevated. You're always being chased. We are not built for that reality.

Lieberman's solution is that we "respectfully and sensibly nudge, push, and sometimes oblige ourselves" to make healthier decisions, to live more in keeping with our biology and to adapt to the modern world with sensible, rational limits. But the mass demand for drugs — the boundless need to opiate and numb ourselves — shows that the simpler solution remains, and will no doubt remain, much more popular. Just take something.

PLUS: Read More Stephen Marche on Esquire.com >>

Follow The Culture Blog on RSS and on Twitter at @ESQCulture.

Stephen Marche Stephen Marche is a novelist who writes a monthly column for Esquire magazine about culture.

This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more information about this and similar content at piano.io