The future of obsessive compulsive disorder (OCD) treatments has taken a major leap forward thanks to the work of scientists at Brown University. For the first time ever, electrical signals in the brain caused by OCD symptoms were recorded in patients as they went about their daily lives. Researchers believe the study could help pave the way for deep brain stimulation as an effective therapy for patients.
Obsessive compulsive disorder is an anxiety disorder which causes persistent unwanted or disrupting thoughts or urges. The repetitive behaviors, such as hand washing, checking on things or meticulous cleaning, can significantly interfere with a person’s daily activities and social interactions.
Many people without OCD have distressing thoughts or repetitive behaviors. However, these thoughts and behaviors do not typically disrupt daily life. For people with OCD, thoughts are persistent, and behaviors are rigid. Not performing the behaviors commonly causes great distress. Many OCD patients know or suspect their obsessions are not realistic; others may think they could be true (known as limited insight). Even if they know their obsessions are not realistic, patients have difficulty disengaging from the obsessive thoughts or stopping the compulsive actions.
OCD affects as much as 2% of the world’s population, and up to 20-40% of cases don’t respond to traditional drug or behavioral treatments.
Deep brain stimulation (DBS) is an elective surgical procedure in which electrodes are implanted into certain brain areas. These electrodes, or leads, generate electrical impulses that control abnormal brain activity. The electrical impulses can also adjust for the chemical imbalances within the brain that cause various conditions. Stimulation of brain areas is controlled by a programmable generator that is placed under the skin in the upper chest.
A limitation is that DBS is unable to adjust to moment-to-moment changes in OCD symptoms, which are impacted by the physical and social environment. But adaptive DBS, which can adjust the intensity of stimulation in response to real-time signals recorded in the brain, could be more effective than traditional DBS and reduce unwanted side effects.
Study senior author David Borton is an associate professor of biomedical engineering at Brown University. “A DBS system that can adjust stimulation intensity in response to symptoms may provide more relief and fewer side effects for patients. But in order to enable that technology, we must first identify the biomarkers in the brain associated with OCD symptoms, and that is what we are working to do in this study,” says Borton, who is also a biomedical engineer in the U.S. Department of Veterans Affairs Center for Neurorestoration and Neurotechnology, in a statement.
Once those biomarkers are positively identified, they could then be used in an adaptive DBS system. Currently, deep brain stimulation systems employ a constant level of stimulation, which can be adjusted by a clinician at clinical visits. Adaptive DBS systems,however, would stimulate and record brain activity and behavior continuously without the need to come to the clinic. When the signal detects symptoms of OCD, it could increase simulation and provide relief to the patient. Likewise, simulation can be decreased as symptoms calm
“This is the first time brain signals from participants with neuropsychiatric illness have been recorded chronically at home alongside relevant behavioral measures,” says study lead author Nicole Provenza, a recent Brown biomedical engineering Ph.D. graduate from Borton’s laboratory. “Using these brain signals, we may be able to differentiate between when someone is experiencing OCD symptoms, and when they are not, and this technique made it possible to record this diversity of behavior and brain activity.”.
This line of research is ongoing. The team seeks to identify a higher set of OCD biomarkers in order to guide the adaptive DBS system. Once those biomarkers are in place, the team hopes to implement their work into a device that will someday be available widespread. The adoption of this device in daily life could be socially and emotionally altering for patients with OCD.
The study is published in the journal Nature Medicine.
Article written by Rhonda Errabelli