ADHD and OCD symptoms: similarities and differences

Can you have both ADHD and OCD?

While it's not very common, it’s possible to have both ADHD and OCD at the same time.

About 1 in 5 children with OCD also have ADHD.^[1] 

In adults, the overlap is less common. Only about 1 in 12 people with OCD also have ADHD.^[2]

Having both conditions can lead to more intense symptoms.

Example: Someone rushes through handwashing or forgets parts of it because of impulsivity. This can make OCD worse, making them feel more anxious and wanting to repeat the ritual.

So what about the children diagnosed with both? Does ADHD just go away as they grow up?

The answer is a bit of both: yes and no.

Younger children with OCD sometimes have slower brain development, which can make their symptoms look like ADHD. But as they grow up, their brain catches up.

By adolescence, the ADHD-like symptoms usually fade, and their brain activity starts to look more like what you’d see in adults with OCD.^[2]

What symptoms do ADHD and OCD share?

ADHD and OCD can both cause problems with paying attention, feeling restless, and acting without thinking. But these problems look different in each condition.

For example:

• If you have ADHD, you might feel restless and keep moving or fidgeting.
• If you have OCD, restlessness might show up as a need to arrange or fix things over and over.

When it’s hard to pay attention:

• ADHD means you might get distracted, daydream, or make careless mistakes.
• OCD means your mind is busy with worries or thoughts, so you might seem “spacey” or distracted because you’re thinking about checking or fixing things.

Here are some symptoms that ADHD and OCD have in common:

What are the differences between ADHD and OCD?

People with ADHD may find it hard to focus, finish tasks, or follow instructions. They might also feel restless or have trouble sitting still.^[3]

OCD, on the other hand, involves obsessions—repetitive, unwanted thoughts—and compulsions, which are repeated behaviours done to ease the anxiety caused by these thoughts.^[4]

So ADHD and OCD are different conditions, but they can sometimes appear similar.

For example, both can make it difficult to focus:

• If you have ADHD, your thoughts might jump around, making it hard to focus on a task.
• If you have OCD, you might keep worrying about germs and feel the need to check things over and over while trying to work.

Another key difference is the direction of behaviour.

This means that:

• ADHD is an externalising disorder, meaning it affects how people interact with the world around them, while:
• OCD is an internalising disorder, where anxiety leads people to turn inward.

Here are some key differences between ADHD and OCD:

References:

1. Abramovitch, A., Abramowitz, J.S. and Mittelman, A. (2013). The neuropsychology of adult obsessive–compulsive disorder: A meta-analysis. Clinical Psychology Review, 33(8), pp.1163–1171. https://doi.org/10.1016/j.cpr.2013.09.004
2. International OCD Foundation. (2010). International OCD Foundation | OCD and ADHD Dual Diagnosis Misdiagnosis and the Cognitive ‘Cost’ of Obsessions.
3. NHS (2021). Symptoms - Attention Deficit Hyperactivity Disorder (ADHD). NHS.
4. NHS (2021). Symptoms - Obsessive Compulsive Disorder (OCD). NHS.