One pushes you to act without thinking, and the other won’t let you stop thinking until you act. When ADHD and OCD occur together, the internal experience can feel like a constant negotiation between chaos and control.
People often assume ADHD and OCD are opposites. One is about impulsivity and distraction. The other is about rigidity and repetition. It would make sense if they cancelled each other out.
Sadly, they don’t.
A 2020 study by Costa and colleagues found that 13.7% of adults with OCD also met criteria for ADHD. Other research puts the figure between 10% and 20%. The overlap is far more common than clinicians once believed. And when both conditions are present, they don’t neutralise each other. They complicate each other.
This is part of why so many people spend years being treated for one condition while the other goes unrecognised. The symptoms mask each other. The behaviours get misread. A thorough ADHD assessment should always consider what else might be present. And the person in the middle is often left wondering why nothing quite fits.
Why ADHD and OCD Get Confused
On the surface, ADHD and OCD can look remarkably similar. Both involve difficulties with attention. Both can cause someone to get stuck on a task or thought. Both can lead to behaviours that seem irrational to outsiders.
The confusion often starts in assessment. A clinician sees someone who can’t let go of a thought, who checks things repeatedly, who struggles to complete tasks. Depending on which symptoms are most visible that day, the diagnosis can go either way. This kind of diagnostic complexity is also common when differentiating OCD from autism.
When OCD Looks Like ADHD
Someone with OCD might appear distractible, but the distraction isn’t random. It’s because their mind keeps pulling them back to an intrusive thought or an urge to perform a ritual. They might lose track of conversations not because they can’t focus, but because a mental compulsion is running in the background.
The procrastination can look the same too. Someone with OCD might avoid starting a task because they’re afraid of doing it imperfectly, and that avoidance gets mistaken for ADHD-related task initiation difficulties. From the outside, the behaviour is identical. The internal experience is entirely different.
When ADHD Looks Like OCD
This happens more often than people realise. Someone with ADHD might develop rigid routines as a way of managing their symptoms. For example, they might check things repeatedly because they don’t trust their memory, or they might get stuck on a topic of interest for hours, which looks like obsessive fixation.
The key difference is motivation. In OCD, the repetitive behaviour is driven by anxiety and a need to neutralise a threat. In ADHD, it’s more likely to be driven by hyperfocus, forgetfulness, or a compensatory strategy that’s developed over time.
Can You Have Both ADHD and OCD?
Yes, and it’s far more common than most people think.
The research on comorbidity has grown substantially over the past decade. A 2019 review by Abramovitch and colleagues in Frontiers in Psychiatry found that roughly 10-20% of adults with OCD also have ADHD. The relationship goes both ways, though not symmetrically. A large 2022 study by Black and colleagues found OCD in about 2.4% of people with ADHD, higher than in the general population but still a minority.
What’s particularly striking is that when both conditions are present, outcomes tend to be worse. Costa and colleagues found that comorbid cases show earlier OCD onset, greater symptom severity, higher rates of suicidality, and more academic and functional impairment. This isn’t just about having two problems instead of one. The combination seems to create its own challenges.
What remains unclear is whether these are two separate conditions that happen to co-occur, or whether there’s a shared underlying vulnerability. A 2016 meta-analysis by Norman and colleagues in JAMA Psychiatry found that both conditions show abnormalities in frontostriatal circuits, the brain networks involved in self-control and response inhibition. The difference is in the direction: ADHD tends towards underactivation of these circuits, OCD towards overactivation. Shared circuits, opposite settings.
For the person living with both, the academic debate is less important than the practical reality: having both conditions means dealing with two sets of neurodivergent symptoms that interact in unpredictable ways.
How ADHD and OCD Present Differently
Understanding the differences matters because it affects treatment. What helps OCD can sometimes make ADHD worse, and vice versa.
| Feature | ADHD | OCD |
| Core driver | Impulsivity, understimulation | Anxiety, threat perception |
| Relationship to thoughts | Thoughts come and go quickly | Thoughts get stuck and demand attention |
| Repetitive behaviour | Often compensatory or interest-driven | Driven by urge to neutralise anxiety |
| Response to interruption | Frustration, moves on | Distress, needs to complete or restart |
| Avoidance | Usually of boring or effortful tasks | Usually of triggers that provoke obsessions |
This isn’t a diagnostic tool. But it gives some sense of how the internal mechanics differ even when the external behaviours look the same.
Compulsions in ADHD
This is where things get particularly confusing. People with ADHD can absolutely engage in compulsive behaviours. But the nature of those compulsions is different from what we see in OCD.
Recent research increasingly views impulsivity and compulsivity as overlapping dimensions rather than opposites. A 2025 review by Yilmaz and colleagues places ADHD closer to the impulsive pole and OCD closer to the compulsive pole, but with considerable overlap between them.
What Compulsive Behaviour Looks Like in ADHD
In ADHD, compulsive behaviours tend to be impulsivity-driven. They might include compulsive spending, compulsive eating, or compulsive phone use. The behaviour happens because the person is seeking stimulation or acting on an urge without pausing to consider consequences.
There’s usually some pleasure or relief in the moment. The regret comes afterwards. These behaviours often co-occur with what researchers call behavioural addictions: excessive gaming, internet use, or similar patterns. They’re best understood as impulsive behaviours that become habitual rather than anxiety-driven rituals.
How This Differs from OCD Compulsions
In OCD, compulsions are anxiety-driven. They’re performed to reduce distress or prevent a feared outcome. Someone might wash their hands repeatedly not because it feels good, but because they can’t tolerate the anxiety of not doing it.
The compulsion itself is often unpleasant. There’s no pleasure in checking the door lock for the fifteenth time. But the alternative, sitting with doubt and uncertainty, feels worse.
Why the Distinction Matters
Treatment for OCD typically involves exposure and response prevention. The person learns to tolerate the anxiety without performing the compulsion. This approach doesn’t translate well to ADHD-related impulsivity, which requires different strategies around impulse control, environmental design, and sometimes medication.
Getting the distinction wrong can mean months or years of treatment that doesn’t address the actual problem.
Intrusive Thoughts: Another Point of Overlap
Both ADHD and OCD involve intrusive thoughts. But again, the relationship to those thoughts is different.
Intrusive Thoughts in OCD
In OCD, intrusive thoughts are experienced as ego-dystonic, which means they feel foreign, unwanted, and contrary to the person’s values. Someone might have a violent thought and be horrified by it. The thought feels like an intrusion, and the person spends significant energy trying to suppress or neutralise it.
The thought itself isn’t the problem. What makes it OCD is the response to the thought: the distress, the attempts to control it, the rituals that develop to manage the anxiety it creates.
Intrusive Thoughts in ADHD
In ADHD, unwanted thoughts happen too, but they tend to be less sticky. The mind wanders constantly, and sometimes it wanders to uncomfortable places. A thought might pop up, cause a moment of discomfort, and then get replaced by the next thing.
The distress is usually lower, and there’s less rumination. The person might forget they even had the thought ten minutes later.
When Both Are Present
When someone has both conditions, they might experience intrusive thoughts with the stickiness of OCD but the unpredictability of ADHD. They might have racing thoughts that keep circling back to a specific worry. The combination can be exhausting.
A 2021 study by Koc and colleagues found something interesting here. People with both OCD and ADHD endorsed obsessive beliefs more strongly than those with OCD alone, particularly beliefs about the importance of controlling their thoughts. The presence of ADHD seemed to make intrusive thoughts feel even more threatening and in need of management. This may help explain why the combination is often more distressing than either condition on its own.
What Happens When Both Conditions Are Present
Living with both ADHD and OCD often feels like being pulled in two directions at once. This internal tension can affect work, relationships, and daily functioning in ways that are hard to explain to others.
The ADHD part wants novelty, stimulation, and freedom from constraints. The OCD part demands order, certainty, and the completion of rituals. One pushes towards chaos. The other insists on control. Neither wins. The person is caught in the middle.
Executive Function Takes a Double Hit
Both conditions independently affect executive function: the ability to plan, organise, prioritise, and regulate behaviour. When both are present, these difficulties compound.
Someone might struggle to start a task because of ADHD-related inertia. Then, once they do start, OCD might demand they do it in a particular way. The task takes three times as long. Frustration builds. Eventually they give up, which triggers guilt, which might trigger more OCD symptoms.
Treatment Becomes More Complex
Stimulant medications, which are often effective for ADHD, can sometimes increase anxiety. This is a problem when OCD is also present. A 2019 review by Abramovitch and colleagues recommends treating both disorders in parallel, often combining an SSRI for OCD with a stimulant or atomoxetine for ADHD. But this requires careful monitoring and usually the involvement of a psychiatrist who understands both conditions.
A 2025 preliminary study by Fukuda and colleagues found that adding ADHD medication to standard OCD treatment showed promising results, with improvements in both sets of symptoms. Case evidence from Masi and colleagues in 2021 suggested similar findings. But the research also notes that stimulants can worsen obsessions in some individuals by increasing focus on feared thoughts. Careful titration and ongoing review are essential.
Therapy approaches need to be integrated too. Standard exposure and response prevention remains first-line for OCD, but adaptations may be needed: shorter sessions, more structure, external reminders, and strategies to accommodate ADHD-related attention difficulties. Pure ADHD coaching, meanwhile, might not address the anxiety driving the OCD symptoms. Treating only one condition often leaves people partially improved.
Getting the Right Diagnosis
Many people with both conditions spend years with only one diagnosis. This happens for a few reasons.
First, clinicians often look for the most obvious explanation. If someone presents with clear OCD symptoms, the assessment might stop there. The ADHD goes unnoticed because the person has learned to compensate, or because their inattention gets attributed to anxiety.
Second, the conditions can mask each other. OCD rituals might impose structure that compensates for ADHD-related disorganisation. ADHD impulsivity might prevent someone from completing the rituals that would make OCD more obvious.
What Thorough Assessment Looks Like
A proper assessment for someone who might have both conditions should include:
- Detailed developmental history going back to childhood
- Exploration of the function behind behaviours, not just the behaviours themselves
- Consideration of how symptoms interact and affect each other
- Assessment of executive function difficulties that might not be captured by standard symptom checklists
- Attention to how symptoms present across different contexts
This takes time. It requires a clinician who is familiar with both conditions and alert to how they overlap.
How Therapy Helps
Understanding that both conditions are present changes the approach. It’s not just about managing OCD or managing ADHD. It’s about addressing the interaction between them.
Therapy might involve adapted exposure and response prevention that accounts for attention difficulties. It might include ADHD-specific strategies for task initiation and organisation. It usually involves helping the person understand their own patterns: which behaviours are driven by anxiety, which are driven by impulsivity, and which are something else entirely.
The goal isn’t to make either condition disappear. It’s to reduce the distress, improve functioning, and help the person stop being caught in the crossfire between two competing sets of demands.
How The Private Therapy Clinic Can Help
If you recognise yourself in what’s described here, whether you’ve already been diagnosed with one condition and suspect the other, or you’re still trying to make sense of what you’re experiencing, we can help. The Private Therapy Clinic offers comprehensive ADHD assessments as well as specialist support for OCD. A free 15-minute consultation can help you work out what the right next step might be.
