Leonard, a writer living near Chicago, was unable to get in the shower; meanwhile, Ross, a teenager, was so terrified of germs he’d shower for seven hours a day. Both suffered from severe obsessive-compulsive disorder and travelled to a Rhode Island hospital to get an experimental brain operation, in which four small holes were burned into their brains. Two years later, Ross is in college, and says the surgery “saved his life.” Leonard saw no change. In the last decade, over 500 people have undergone brain surgery for everything from depression to obesity, the New York Times reports. This year, for the first time since frontal lobotomy fell out of favour over 50 years ago, the Food and Drug Administration approved one type of surgery for some kinds of OCD. But there are risks: some psychiatrists and medical ethicists say doctors still don’t know enough about it, and results can be unpredictable, with a few people even getting worse. With demand for these operations so high, some less experienced surgeons could begin offering them without oversight or support. In one procedure, called cingulotomy, doctors drill into the skull and thread wires into the brain, destroying pinches of tissue along a circuit in each hemisphere that connects emotional centres of the brain to the frontal cortex, where conscious planning happens. This circuit seems to be hyperactive in people with severe OCD.