After decades of prohibition, research is illuminating new uses for some illegal drugs. In the 1960s, drug scares swept the nation. In 1970, the Controlled Substances Act was passed, banning or restricting the use of some of these drugs, due in part to the political climate of the time. For 40 years, research into these drugs was prohibited. In a paper , former chair of the U.K. Advisory Council on the Misuse of Drugs, David Nutt, called these drug laws “the worst case of scientific censorship since the Catholic Church banned the works of Copernicus and Galileo.” Today, the Food and Drug Administration (FDA) is permitting study into many drugs that were once banned. Research is also occurring in other countries with more relaxed drug policies than the United States. And scientists are finding that some illegal drugs have significant medicinal uses.

1. Heroin for Opiate Addiction The majority of opiate addicts don’t use heroin. They’re addicted to pharmaceutical opiates, such as Vicodin, Percocet, Oxycontin, or Demerol. And almost invariably, they’re using opiates to self-medicate an underlying psychiatric condition, such as anxiety, depression, flashback memories, nightmares, or sleep disorders. “It appears that these psychiatrically severely ill people simply need a medication,” said Dr. Torsten Passie, of the Hannover Medical School in Germany, in an interview with Healthline. Users of opiates are also likely to use alcohol, marijuana, and benzodiazepines to try to control their symptoms. Passie found that compared to methadone, the opiate drug currently used to treat addiction to opiates, patients taking heroin reduced their use of other drugs by a third, with 60 percent of patients stopping the use of all other drugs within the first year. He also found that after four weeks of heroin use, patients no longer experienced any intoxicating effects from the drug, bolstering the theory that they’re not just taking drugs to get high. “There is no detectable intoxication in most of them. Neuropsychological results show that they can perform mostly so well that even car driving would have to be allowed,” said Passie. “This is not true when additional substances were taken, right?” Passie hopes that his work will change the way people think about addicts (or, as he calls them, heroin-using humans). “Because other substances do not help them sufficiently, we are kind of nonsensical putting people who need a strong medication for their strong symptoms in prisons instead of treating them with respect and dignity as patients,” he said. Learn the Basics of Opioid Addiction »

2. Ketamine for Bipolar Disorder Although ketamine is not completely banned, it’s still strictly regulated, and is used primarily as a sedative. A study published in 2012 found that it might have other uses. Dr. Demitri Papolos, Director of Research at the Juvenile Bipolar Research Foundation, examined ketamine as a treatment for bipolar disorder in children. Current medications for bipolar disorder can take weeks or months to fully come into effect. Many patients struggle to find the right combination of drugs that will give them relief, meaning that new drugs offer patients valuable new options. Papolos found that the children treated with ketamine showed an immediate improvement in their symptoms, and that the improvements lasted for almost two weeks after they stopped using ketamine. Side effects were minimal once the children got used to the drug. See How ‘Special K’ May Have Antidepressant Effects »

3. MDMA for Post-Traumatic Stress Disorder Although there are many treatments for post-traumatic stress disorder (PTSD), some people are resistant to them. “Common reasons for this are that, when people revisit their traumatic experiences in therapy, they may be either emotionally flooded or emotionally numb, and either one gets in the way of successful therapeutic processing,” explained Dr. Michael Mithoefer, an assistant professor at the Medical University of South Carolina, in an interview with Healthline. Mithoefer has begun a series of studies treating PTSD in veterans who haven’t responded to conventional therapies. The MDMA doesn’t replace therapy, but adds to it. Patients received two to four doses of MDMA, spaced at least one month apart, to augment their therapy. “MDMA seems to give people a period of time in which they connect with their emotions but are not overwhelmed by them, a sense that ‘this is difficult, but I can do it,’” said Mithoefer. In his pilot study, every single patient treated saw a reduction in their PTSD symptoms, often taking them below the threshold for the disorder. One patient even appeared to be cured after a single dose. Eleven to 20 percent of veterans of the wars in Iraq and Afghanistan show signs of PTSD, often leaving them on lifetime disability. A drug that could not just treat PTSD but outright cure it would be invaluable. Read More About PTSD »