What Causes OCD?
Published October 24th, 2024
5.5 min read
While there isn’t one singular cause of OCD, many different factors play a role.
Written by Simon Spichak
Obsessive-compulsive disorder (OCD) is one of the most common and misunderstood mental health conditions, affecting one in every 40 people worldwide. Although OCD has been studied and treated for decades, scientists can’t pinpoint an exact cause. However, they think multiple factors play a role.
Symptoms of OCD
Many people think that OCD is a quirky obsession with cleanliness and organization. But this portrayal is far from accurate.
OCD has two hallmark components — obsessions and compulsions.
Obsessions are unwanted thoughts and desires, while compulsions are repetitive behaviors. OCD can be incredibly distressing as it can derail relationships, make it harder to stay organized, and make it challenging to stay productive at work.
Is OCD linked to changes in brain structure and function?
Scientists have studied the brains of people with OCD using brain scans.
Recent research pooled data from dozens of other studies on the topic to see if there are any consistent changes in the brain associated with OCD. It looked at the size of different brain regions, how well they connect, and how they function.
The study found that multiple brain regions are affected in OCD, including the medial prefrontal cortex (mPFC), the anterior cingulate cortex (ACC), the thalamus, and the striatum.
The mPFC and ACC are important in higher-order thinking and executive function. The thalamus acts as the information gateway for other senses, and the striatum is involved in decision-making.
While there might be some differences in brain structure and function, we aren’t sure what these changes mean. It is hard to differentiate cause and effect. It is difficult to tell whether OCD causes changes in the brain or if the brain changes are causing OCD.
Scientists use brain scans to look for unique changes in brain structure and function in OCD | Photo by cottonbro studio.
Is OCD genetic?
Like in many other mental health conditions, there is a genetic component to OCD. If someone in your family has OCD, you are seven times more likely to develop the condition than someone who comes from a family without OCD.
OCD risk is polygenic, meaning that many genes have small contributions to your risk. You might inherit a whole bunch of genes from your parents that bump up your risk substantially together. However each gene alone might only increase your risk by a very, very small amount.
But still, many people who have parents with OCD never develop the condition. Why is that? A combination of factors, including your upbringing, also play a role. The combination of all these different factors might determine why some people who have OCD in their family never develop the condition.
Is OCD caused by a chemical imbalance?
A common misconception is that a chemical imbalance in the brain causes mental health conditions. It posits that the brain isn't producing enough neurotransmitters, like serotonin, leading to symptoms. Serotonin plays many different bodily roles, including regulating digestion, immune function, blood clotting, mood, and sleep.
Many drugs developed to treat mental health conditions were thought to affect the levels of neurotransmitters like serotonin, birthing this idea.
Since the early days of neuroscience research, we've learned that the way these drugs work is far more complex. Serotonin might play a role, but it doesn't cause OCD.
Also, measuring the levels of different neurotransmitters in the brain is very hard as we simply don't have the technology. As with all the other causes, this is just one factor that might play a role in the condition.
Visualization of serotonin being released to communicate with a nearby cell| National Institute on Drug Abuse, Public domain, via Wikimedia Commons
Can stress or trauma cause OCD?
There is some evidence that experiencing stress or trauma while you’re young, or even while your mother is pregnant, could bump up the risk of developing OCD. Emotional abuse or trauma might interact with other factors in your life, such as your brain chemistry and genetics, that affect your risk.
Can infections trigger OCD?
Kids can develop disorders after infections that resemble OCD.
PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections) and PANS (Pediatric Acute-onset Neuropsychiatric Syndrome) occur after an infection. The body’s immune system goes haywire, leading to inflammation and other changes in the brain.
Overnight, kids can develop symptoms resembling OCD that have a very severe impact on their daily lives. Diagnosing PANDAS/PANS is hard because it is sometimes difficult to link the condition to a previous infection.
There is evidence that other viruses, including SARS-CoV-2, can trigger the development of certain mental health conditions. Scientists are still studying these links to understand how.
Takeaway
Many different factors play a role in OCD. It is unlikely that one of these factors is the sole cause. Likely, it is a combination of changes in the brain, genetics, neurochemicals, early-life stress, and infections that affect your susceptibility to the condition.
If you want to read more about OCD, you can take a look at our other guides:
You can learn more about the condition through the International OCD Foundation, the Canadian Mental Health Association, and BeyondOCD.org.
Resolvve also offers low-cost therapy options for OCD. If you’re interested, you can find a therapist or book a free consultation today.
Please note that this post is written for educational purposes; it is not therapy. If you need to talk to a professional, please book a consultation with a psychotherapist through Resolvve.
