They analyzed a variety of popular methods and calculated how much it would cost to use each method to reduce cocaine consumption in the US by 1%. Source-country control — military programs to destroy drug production in countries like Peru, Bolivia, and Colombia — are not just devastating to poor third-world citizens; they’re also the least effective, costing $783 million for a 1% reduction. Interdiction — seizing the drugs at the border — is a much better deal, costing only $366 million. Domestic law enforcement — arresting drug dealers and such — is even better, at $246 million. But all of those are blown completely out of the water by the final option: funding treatment programs for drug addicts would reduce drug use by 1% at a cost of only $34 million.

In other words, for every dollar spent on trying to stop drugs through source-country control, we could get the equivalent of twenty dollars benefit by spending the same money on treatment. This isn’t a bunch of hippy liberals saying this. This is a government think tank, sponsored by the US Army.

• Read the study.

Bruce Alexander was skeptical about these results. He noticed that the rats in the experiments were stuffed alone in a boring cage with little else to do. “If I was strapped down alone in a cage,” he thought, “I’d probably want to get high too.”

So he built a rat park — a large, intricate, brightly-painted and heavily-padded structure to make the rats actually happy. He put half the rats in the normal cages and half in the park and gave both equal access to drugs.

The rats in the cage got addicted, while the rats in the park stayed away.

Then, even more strikingly, he took rats who’d had 57 days to get addicted to the drugs and took half of them out of the cages and put them in the park. The rats, even though they’d been addicted in the cage, suddenly stayed away from the drugs. They even voluntarily detoxed — trembling and shaking, but still staying off the drugs.

The top-shelf journals like Science and Nature rejected the study. It did end up getting published in a peer reviewed journal (Pharamacology, Biochemistry and Behavior, impact factor 1.5), but received little public attention. His university pulled the funding for the project.

• The paper [PDF]
• Detailed Wikipedia article
• Related paper by the study’s author