Methadone is commonly given to people trying to kick a heroin addiction. But the long-lasting opioid is also an inexpensive, effective pain-killer. With rising costs of prescription narcotics like OxyContin, doctors are increasingly prescribing methadone to treat pain, especially to patients on Medicaid or less generous health insurance plans. From 1999 to 2005, its use in the U.S. increased more than five-fold, according to the U.S. Drug Enforcement Administration. But over the same time period, deaths associated with the drug have increased more than five times, climbing from 786 in 1999 to 4,462, according to the CDC. In Washington state alone, more than 2,100 people died after taking the drug since 2003, says says The Seattle Times.
Placebos are inactive treatments that shouldn’t, in some sense, have a real effect. And yet they often do. But the chemical basis of the placebo effect, despite its enormous importance, is still largely a mystery. A study published this week in Nature Medicine shows that cannabinoid receptors are involved in the placebo response to pain, which hasn’t been demonstrated before. The finding implies that the brain’s own endocannabinoids can fight pain, and actually do it via the same pathway as several compounds in the cannabis plant.