Chinese researchers try brain implants to treat drug addicts

The sound of doctors boring through his skull to feed electrodes deep into his brain made Yan tremble.

"The drill was like bzzzzzzz," he later recalled. "The moment of drilling is the most terrible." Yan is a methamphetamine addict. The hope is that technology will extinguish his addiction quite literally, with the flip of a switch.

The treatment deep brain stimulation has long been used for movement disorders like Parkinson's. Now, the first clinical trial of DBS for methamphetamine addiction is being conducted at Shanghai's Ruijin Hospital, along with trials for opioid addicts. Yan is the study's first patient; for fear of losing his job, he asked that only his surname be published.

Western attempts to push forward with human trials of deep brain stimulation for drug addiction have foundered, even as China has emerged as a hub for this kind of research.

But the vast suffering wrought by the US opioid epidemic may be changing the risk-reward calculus for doctors and regulators. Now, the experimental surgery Yan underwent is coming to America. In February, the US Food and Drug Administration greenlighted a clinical trial in West Virginia of DBS for opioid addicts.

Until now, complex ethical, social and scientific questions made it hard to push forward with such experiments in the United States, where the devices can cost $100,000 to implant. Scientists in Europe have struggled to recruit patients for their DBS addiction studies.

Globally, there are eight registered DBS clinical trials for drug addiction, according to a U.S. National Institutes of Health database. Six are in China.

China has a long, troubled history of using brain surgery to treat addiction. Doctors destroyed small clumps of tissue in the brains of heroin addicts, garnering huge profits and leaving behind a trail of patients with mood disorders, lost memories and altered sex drives.

In 2004, China's Ministry of Health ordered a halt to the practice at most hospitals. Nine years later, a military hospital in Xi'an reported that roughly half of 1,167 addicts who had their brains lesioned stayed off drugs for at least five years.

DBS builds on that history. The surgery involves implanting a device that acts as a kind of pacemaker for the brain, electrically stimulating targeted areas. Instead of irreversibly killing brain cells, the devices allow interventions that are in theory reversible. The technology has opened a fresh field of human experimentation globally.

"For many other psychiatric disorders, for example, anorexia schizophrenia, OCD, there's no way to use the animal to be like a model," said Dr. Sun Bomin, director of the functional neurosurgery center at Ruijin Hospital. "For these kinds of special psychiatric disorders we have to use human patients." Some believe such human experiments on drug addicts should not be allowed.

Critics argue that they are premature, and will not address the complex biological, social and psychological factors that drive addiction. Scientists don't fully understand how DBS works and there is still debate about where electrodes should be placed to treat addiction.

There is also skepticism in the global scientific community about the general quality and ethical rigor of clinical trials done in China.

"It would be fantastic if there were something where we could flip a switch, but it's probably fanciful at this stage," said Adrian Carter, who heads the neuroscience and society group at Monash University in Melbourne. "There's a lot of risks that go with promoting that idea."