Scientists have identified brain signals closely associated with compulsive symptoms. It can ultimately – especially for people with a difficult or even untreatable compulsion – lead to an effective tailor-made treatment.

It is estimated that up to 2 percent of the world’s population is affected by it: an obsessive compulsive disorder, also known as OCD or obsessive-compulsive disorder. People who have to deal with this have obsessive thoughts and actions. The disorder often has a huge influence on functioning. There are therapies and medicines that can help, but they do not work or do not work sufficiently for 20 to 40 percent of patients. For people who do not benefit from medication or therapy, there is another option: deep brain stimulation. Electrodes are placed in the brain and those electrodes constantly emit mild pulses. While this approach works for about half of patients who do not respond to other treatment methods, it also has a major drawback. For example, the brain is constantly stimulated to the same extent, while this is actually not necessary. “OCD is a disorder in which the severity of symptoms varies greatly over time,” said study researcher David Borton. This is partly because symptoms are often triggered by events in the environment. A patient actually benefits more from a system that can adjust the degree of brain stimulation to the severity of the symptoms. “That may bring more relief and fewer side effects,” says Borton.

Customization

Until recently, such ‘customized stimulation’ was unthinkable. “To enable this technology, we first need to identify the biomarkers associated with OCD symptoms in the brain,” Borton said. And that is exactly what Borton and colleagues have now done. And with that, a more effective treatment for patients with a difficult-to-treat OCD now seems to be getting closer.

The research

The researchers collected five people with severe obsessive-compulsive disorder who were eligible for deep brain stimulation. A device was placed on each of the clients that was able to stimulate the brain and monitor the brain signals. The subjects were sent home, where their brain activity was therefore continuously monitored. Biometric data was also collected – using a smartwatch, such as their heart rate and activity level. In addition, the test subjects regularly returned to the lab where the researchers recorded their facial expressions and body movements – again simultaneously with the brain signals. The researchers then placed the brain signals next to all the data collected simultaneously, hoping to find correlations. “It is the first time that brain signals from people with a neuropsychiatric disease, together with relevant behaviors, have been continuously monitored in the home environment,” said researcher Nicole Provenza. “Using these brain signals, we are able to distinguish between the moment when someone does show OCD symptoms and a moment when they are not bothered by them.”

It is the prelude to more. “Now we know we have the tools to identify signals that we can use to adjust the level of stimulation according to the symptoms,” Borton said.

Follow-up research

But before such ‘customized stimulation’ can really be used, more research is needed first. For example, the scientists would like to repeat their study among a much larger group of test subjects. They point out that obsessive-compulsive disorder is a complex disorder that can manifest itself in very different ways. And of course, by studying more patients, they hope to stumble upon brain signals that would make it possible to offer the tailor-made stimulation to people with a variety of symptoms. If successful, the next step would be to find a manufacturer that would develop a device that actually stimulates the brain when needed. “Our goal is to understand what these brain signals are telling us and train the device to recognize certain patterns associated with specific symptoms,” said study researcher Sameer Sheth.

In addition to tailor-made stimulation, the research may also lead to other effective treatments, says researcher Wayne Goodman. “The study may increase our understanding of the processes in the brain that underlie the disorder. And a better understanding of that could allow us to find new anatomical targets for new treatments that are much less invasive than deep brain stimulation.”