Researchers discover brain inflammation in people with OCD

June 21, 2017, Centre for Addiction and Mental Health
Credit: copyright American Heart Association

A new brain imaging study by the Centre for Addiction and Mental Health (CAMH) shows for the first time that brain inflammation is significantly elevated - more than 30 per cent higher - in people with obsessive-compulsive disorder (OCD) than in people without the condition. Published today in JAMA Psychiatry, the study provides compelling evidence for a new potential direction for treating this anxiety disorder, which can be debilitating for people who experience it.

"Our research showed a strong relationship between and OCD, particularly in the parts of the brain known to function differently in OCD," says Dr. Jeffrey Meyer, senior author of the study and Head of the Neuroimaging Program in Mood & Anxiety in CAMH's Campbell Family Mental Health Research Institute. "This finding represents one of the biggest breakthroughs in understanding the biology of OCD, and may lead to the development of new treatments."

Inflammation or swelling is the body's response to infection or injury, and helps the body to heal. But, in some cases, this immune-system response can also be harmful, says Dr. Meyer, who holds a Canada Research Chair in the Neurochemistry of Major Depression. Dampening the of and promoting its curative effects, through new medications or other innovative approaches, could prove to be a new way to treat OCD. In an earlier study, Dr. Meyer discovered that brain inflammation is elevated in people with depression, an illness that can go hand in hand with OCD in some people.

A novel direction for developing treatments is important, since current medications don't work for nearly one in three people with OCD. About one to two per cent of adolescents and adults have OCD, an anxiety disorder in which people have intrusive or worrisome thoughts that recur and can be hard to ignore.

The study included 20 people with OCD and a comparison group of 20 people without the disorder. Doctoral student Sophia Attwells was first author of the study. The researchers used a type of brain imaging called (PET) that was adapted with special technology at CAMH to see inflammation in the brain. A chemical dye measured the activity of immune cells called microglia, which are active in inflammation, in six brain areas that play a role in OCD. In people with OCD, inflammation was 32 per cent higher on average in these regions. Inflammation was greater in some people with OCD as compared to others, which could reflect variability in the biology of the illness.

Additional investigations are under way to find low-cost blood markers and symptom measures that could identify which individuals with OCD have the greatest level of inflammation and could benefit the most from treatment targeting inflammation. Another notable finding from the current study - a connection between resisting compulsions and brain inflammation - provides one indicator. At least nine out of 10 people with OCD carry out compulsions, the actions or rituals that people do to try to reduce their obsessions. In the study, people who experienced the greatest stress or anxiety when they tried to avoid acting out their compulsions also had the highest levels of inflammation in one brain area. This stress response could also help pinpoint who may best benefit from this type of treatment.

The discovery opens different options for developing treatments. "Medications developed to target brain inflammation in other disorders could be useful in treating OCD," says Dr. Meyer. "Work needs to be done to uncover the specific factors that contribute to inflammation, but finding a way to reduce inflammation's harmful effects and increase its helpful effects could enable us to develop a new treatment much more quickly."

Explore further: New biological evidence reveals link between brain inflammation and major depression

More information: JAMA Psychiatry (2017). DOI: 10.1001/jamapsychiatry.2017.1567

Related Stories

New biological evidence reveals link between brain inflammation and major depression

January 28, 2015
A new study by the Centre for Addiction and Mental Health (CAMH) found that the measure of brain inflammation in people who were experiencing clinical depression was increased by 30 per cent. The findings, published today ...

Researchers identify how inflammation spreads through the brain after injury

March 8, 2017
Researchers have identified a new mechanism by which inflammation can spread throughout the brain after injury. This mechanism may explain the widespread and long-lasting inflammation that occurs after traumatic brain injury, ...

Study pinpoints key pathway in inflammation and aging

May 9, 2017
In patients with colitis, a serious condition affecting the gut, the immune system turns against the body's own microbes, causing inflammation. To combat this inflammation, scientists have focused in on a chemical signal ...

Brain inflammation linked to depression in multiple sclerosis

July 7, 2016
Patients with multiple sclerosis have higher rates of depression than the general population, including people with other life-long disabling diseases. Symptoms of multiple sclerosis arise from an abnormal response of the ...

Inflammation attacks brain's reward center

February 2, 2016
A new study by Neil Harrison and colleagues published in Biological Psychiatry suggests that a brain reward center, the striatum, may be directly affected by inflammation and that striatal change is related to the emergence ...

Connection between brain inflammation and CTE identified

November 2, 2016
For the first time, researchers have shown that inflammation in the brain may have direct involvement in the development of chronic traumatic encephalopathy (CTE). In addition, they found that the number of years one plays ...

Recommended for you

Perinatal hypoxia associated with long-term cerebellar learning deficits and Purkinje cell misfiring

August 18, 2018
Oxygen deprivation associated with preterm birth leaves telltale signs on the brains of newborns in the form of alterations to cerebellar white matter at the cellular and the physiological levels. Now, an experimental model ...

People are more honest when using a foreign tongue, research finds

August 17, 2018
New UChicago-led research suggests that someone who speaks in a foreign language is probably more credible than the average native speaker.

Critical role of DHA on foetal brain development revealed

August 17, 2018
Duke-NUS researchers have found evidence that a natural form of Docosahexaenoic Acid (DHA) made by the liver called Lyso-Phosphatidyl-Choline (LPC-DHA), is critical for normal foetal and infant brain development, and that ...

FDA approves brain stimulation device for OCD

August 17, 2018
(HealthDay)—A brain stimulation device to treat obsessive-compulsive disorder (OCD) has received approval for marketing Friday by the U.S. Food and Drug Administration.

Automated detection of focal epileptic seizures in a sentinel area of the human brain

August 17, 2018
Patients with focal epilepsy that does not respond to medications badly need alternative treatments.

Research eyes role of stress in mental illnesses

August 17, 2018
We all face stress in our lives. Even researchers seeking to understand why some people shrug it off while others face battles against disorders like depression or PTSD.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.