• Posted June 30, 2023

Science Brings New Insight Into Origins of OCD

California psychiatrist Dr. Carolyn Rodriguez once had a patient with obsessive-compulsive disorder (OCD) who washed his hands so often that he had to wear gloves to cover his cracked and swollen skin.

“People with intrusive thoughts of contamination can do this for hours on end with scalding hot water,” said Rodriguez, who is also associate dean for academic affairs at Stanford University School of Medicine.

Though OCD is fairly common, with around 2 in every 100 adults in the United States affected, according to the Stanford Center for Health Education, its causes have not been well understood.

Until now.

Psychologists from the University of Cambridge in the U.K. report they have found widespread chemical imbalances in the regions of OCD patients' brains responsible for decision-making, specifically involving the major neurotransmitter chemicals cortical glutamate and GABA. The findings could lead to more targeted treatments for the condition, they added.

OCD is a mental health condition that “involves both obsessions and compulsions that take up a lot of time and get in the way of important activities, such as school, family life, extracurricular activities, developing friendships, and self-care," according to the International OCD Foundation.

OCD doesn't look the same in each individual. People with the condition can have intrusive thoughts of harm toward themselves or others, intrusive thoughts of contamination, symmetry obsessions or checking compulsions.

“Some people can have thoughts that they ran somebody over. So they have to go back to the street and check that they didn't run somebody over or have to watch the news to check,” said Rodriguez.

Treatments like selective serotonin reuptake inhibitors (SSRIs), cognitive behavioral therapy, transcranial magnetic stimulation, and even brain surgery in severe cases, are used to treat patients with OCD.

"There's quite a lot known about OCD, for example, the neural systems which seem to be impaired in OCD," said study author Dr. Trevor Robbins, a professor of cognitive neuroscience at Cambridge. “There are quite a few treatments as well … [But] one of the problems there is that we don't really understand in detail how many of these treatments really work.”

To make matters worse, Rodriguez said it takes an average of 17 years before a patient with OCD symptoms even receives treatment. And only half of patients will improve with standard treatments, according to the Stanford Center for Health Education.

For the study, the Cambridge scientists used a 7-Tesla proton magnetic resonance spectroscopy, one of the most powerful imaging machines in existence, to measure OCD patients' brains against healthy controls. They found the balance between glutamate and GABA is “disrupted” in OCD patients in two frontal regions of the brain. The degree of chemical imbalances was also found to correlate with OCD symptom severity.

The report was published June 27 in the journal Nature Communications.

“Some people are so overcome with their obsessions and compulsions that they don't even leave their houses for months on end. So it can be really, really bad,” said Robbins. “So, therefore, it's very important to try and understand its neural and biological basis to try and improve treatments.”

Rodriguez was excited by the findings, and the possibility of unlocking more important information about the condition.

“We don't know what causes OCD at the end of the day, and what we need in the field are studies that help us move toward an understanding of what is OCD in the brain, how can we treat it better, and these kind of basic mechanistic studies that help us understand what OCD is in the brain can help lead to treatments and help the suffering of the patients,” she said.

More information

The International OCD Foundation has more on obsessive-compulsive disorder.

SOURCES: Trevor Robbins, PhD, professor, cognitive neuroscience, Cambridge University, U.K.; Carolyn Rodriguez, MD, PhD, associate dean, academic affairs, Stanford University School of Medicine, Stanford, Calif.; Nature Communications, June 27, 2023