France's ethics commission has given the go-ahead for clinical trials of neurosurgery on patients with obsessive-compulsive disorder (OCD), a debilitating psychiatric condition.
The ruling by the National Consultative Committee on Ethics will allow researchers to conduct carefully controlled trials using neurostimulation — a technique that involves stimulating a targeted area of the brain using implanted electrodes connected to a battery.
Neurosurgery was virtually abandoned as a treatment of psychiatric illness throughout the world after public revulsion over the abuse of lobotomies half a century ago. However, progress in neuroscience has led to renewed interest in such interventions, raising some thorny ethical questions.
Neurostimulation has the advantage of being reversible and, because the stimulator can be switched on and off and the electrodes removed, blind control trials can be carried out on consenting patients. OCD is a leading contender for such trials because it is well understood and therefore easy to target in the brain. What's more, its sufferers, unlike most other psychiatric patients, can often give informed consent to surgery. In both the United States and Europe, ethics committees decide whether the patients can give consent on a case-by-case basis.
Last October, Alim-Louis Benabid, a neurosurgeon at the Joseph Fourier University in Grenoble, asked the French commission to consider the ethics of using neurostimulation on OCD patients. The technique has been used to treat movement disorder in Parkinson's disease, but it has been tried on only about 20 OCD patients in Belgium, Sweden and the United States in the past five years.
Experimental surgical techniques are not constrained by France's bioethics laws, but Benabid says that he wanted an opinion from the ethics commission before starting clinical trials. The commission decided in favour of using neurostimulation, but said that strict experimental conditions should apply, including the setting up of a committee to oversee the choice of patients, their consent, and the evaluation of results.
The commission added that the experiment should involve only the most severe cases of OCD. Sufferers perform rituals, such as washing their hands, hundreds of times a day. Around 1–2% of people are thought to be affected, with some 10% of sufferers showing severely debilitating symptoms.
Bart Nuttin, a neurosurgeon from the Catholic University of Leuven in Belgium, told the commission that he was working with others to draft a scientific and ethical framework for using the technique before it becomes widely established.
“We were very concerned about this technique falling into the wrong hands,” Nuttin says, adding that the journal Neurosurgery has accepted the group's proposed guidelines for publication later this year.
However, progress in functional brain imaging is also tempting researchers to try to use neurostimulation to treat other psychiatric illnesses, such as depression, where such issues as the identification of the organic basis of the disorder and informed consent are even more complex.