OCD and ADHD: What Are the Differences?

Attention deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD) are both conditions that can make it difficult for people to pay attention, hindering the ability to function at school or work.

ADHD and OCD affect similar parts of the brain: Both conditions may cause a person to take a long time to get things done, or they may cause difficulty in relationships with others. However, there are also key differences between the two conditions, including the fact that ADHD is much more common, especially in children. 

In some people, symptoms of OCD can overlap with the symptoms of ADHD. Here’s what you should know about ADHD, OCD, and whether the conditions can occur together. 

Attention Deficit Hyperactivity Disorder

ADHD is a neurodevelopmental disorder that, by some estimates, affects about 11% of school-age children and about 4% of adults. The symptoms of ADHD can present in different ways, depending sometimes on a person’s sex or age.

The symptoms usually fall into these three categories:

• Inattention: Trouble staying focused and organized
• Hyperactivity: Talking or moving constantly
• Impulsivity: Trouble with self-control

These can present as common symptoms, including: 

• Forgetfulness and disorganization
• Trouble focusing or completing a task
• Avoiding tasks that are tedious or challenging
• Fidgeting or restlessness
• Trouble getting along with others 

Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a chronic mental health illness in which intrusive, recurring thoughts (obsessions) and behaviors (compulsions) are repeated over and over again, to the point that they interfere with a person’s functioning.

OCD occurs in 2.3% of people. Although it’s most often diagnosed in adulthood, research indicates that OCD can occur in a small percentage of children as well.

OCD is structured around these two primary categories of symptoms:

• Obsessions manifest as repeated thoughts, urges, or mental images that are involuntary, disturbing, and anxiety-inducing. 
• Compulsions are repetitive behaviors that are done in response to or in hopes of controlling an obsession.

These core symptoms can manifest in common symptoms of OCD, including:

• Fear of contamination resulting in frequent washing
• A need for order and an inability to move on until items are perfectly ordered
• Aggressive thoughts toward self or others

OCD and ADHD Similarities

At first glance, OCD and ADHD appear to be very different. However, they have a number of commonalities, which can make it difficult to get a proper diagnosis. 

Affected Regions of the Brain

People with OCD and patients with ADHD both experience abnormalities in the brain's frontostriatal circuits, the neural pathways that connect the frontal lobes of the brain with the ganglia.

A 2020 study found that ADHD was associated with a reduced brain volume in these areas. A 2017 study found that people with OCD had functionally abnormal connections in the frontostriatal circuits compared to healthy individuals.

Potential for Interfering With School and Work

ADHD and OCD both make it difficult for people to complete a task. People with ADHD might not have the ability to focus on a task until completion, while people with OCD have their focus continually interrupted by obsessive thoughts and compulsions.

Because of these difficulties regulating attention, people with OCD and ADHD often struggle to reach their full potential at school and work. This is not due to their cognitive abilities, but due to the symptoms of their disorder.

Relationships With Others

ADHD and OCD both can complicate relationships with others. Symptoms of ADHD, including lack of impulse control and insistent talking, can make friendships difficult for kids and adults. And for people with OCD, the time that is dedicated to certain obsessions and compulsions can make relationships difficult, particularly if the obsessions they are experiencing are violent or sexual in nature. 

Development of Other Disorders

People with ADHD or OCD are at an increased risk for developing other disorders or health conditions, including:

• Depression: A significant percentage of people with ADHD will experience symptoms of depression during their lifetime. People with OCD are also at increased risk of depression, especially right after OCD symptoms begin.
• Sleep disorders: Between 25% and 50% of people with ADHD are estimated to also have sleep problems. It is quite frequent for people with OCD to also have insomnia.
• Gastrointestinal (GI) disorders: People with ADHD are more likely to have gastrointestinal disorders. People with OCD are at higher risk for irritable bowel syndrome (IBS, disorder of the large intestine) and often experience more severe symptoms than those without OCD.

Risk factors

OCD and ADHD share risk factors, including:

• Genetics: Both conditions tend to run in families.
• Stress: Feeling under stress can make the conditions of both disorders worse.
• Trauma: Experiencing trauma, especially in childhood, raises risk for both conditions and can make symptoms worse.

OCD and ADHD Differences

Although OCD and ADHD can have some similar effects on a person’s life, they are very different disorders. One distinguishing difference between OCD and ADHD can be risk tolerance. People with OCD tend to avoid risk and strive to be in control, whereas people with ADHD tend to be impulsive. 

These opposite effects are seen in the brains of people with OCD and ADHD. People with OCD have more activity in the affected frontostriatal area, whereas people with ADHD have less.

OCD is generally considered an internalizing disorder, which means that the symptoms cause internal stress. ADHD is often considered an externalizing disorder, which means that the symptoms impact how a person interacts with their environment. 

Finally, about 40% of kids with ADHD will outgrow the condition by the time they reach adulthood, whereas people with OCD will often have to manage the condition throughout their lives. 

Treatment and Outlook

Both OCD and ADHD are chronic conditions that can be treated with behavioral and medical interventions. The conditions are treated differently so it's important to see your healthcare provider to ensure you get an accurate diagnosis.

Treatment for ADHD typically includes behavioral modifications based on symptoms, therapy, and prescription medications, often psychostimulants. The treatment for OCD involves cognitive therapies and medications, often antidepressants.

Can OCD and ADHD Co-Occur?

Some people with OCD can present with symptoms—like inattention—that might be misdiagnosed as ADHD. Because of this, a 2017 study recommended that healthcare providers treat OCD first, then address symptoms of ADHD in individuals who present with symptoms of both conditions.

If you suspect that you or a loved one is dealing with both ADHD and OCD, talk with a trusted healthcare professional who is experienced in treating co-occurring mental health disorders. Research in this area is constantly changing, as are treatment recommendations. Your healthcare provider will help develop a plan that is specific to you.

Summary

ADHD and OCD are two different conditions that can present with some similarities. Both may trigger an inability to focus or sit still or trouble getting along with others. However, there are key differences, including how each condition affects brain activity and how their symptoms and behaviors present. It's important to see a healthcare provider for an accurate diagnosis.

A Word From Verywell 

Both ADHD and OCD can interfere with your ability to reach your full potential at school or work. In some cases, people with OCD can exhibit symptoms that mimic those of ADHD.

Scientists are still learning about the connection between these complex conditions. If you’re living with one or both, find a trusted healthcare provider who will work with you on a treatment regimen that helps you reach your goals.