Emerging research suggests that many people with OCD may have undiagnosed autism, and many of us live with both. That makes this less of an either/or question and more of an “and” conversation.
Given the overlap, it can be hard to tease out the difference (and the co-occurrence). This raises the risk of being diagnosed with one while the other goes unrecognized and unsupported, as one 2019 deep dive in Spectrum explored.
Table of Contents
What Is OCD?
OCD is characterized by persistent, distressing thoughts, ideas, or sensations that cause significant fear and anxiety (obsessions), followed by specific behaviors such as handwashing or checking doors (compulsions) that are meant to reduce the obsessions. To be diagnosed, obsessions or compulsions must be time-consuming (for example, more than an hour a day) or cause significant distress or interfere with daily life (American Psychiatric Association).
Obsessive and intrusive thoughts tend to cluster around similar themes.
Some common obsessions include:
Fear of contaminationWorries about having left appliances on or doors unlockedFear of acting in shameful or humiliating waysDiscomfort with things being out of orderUnwanted sexual thoughts or imagesHealth anxietyExcessive thoughts about religion, guilt, shame, or purity
Some common compulsions include:
Excessive cleaning and handwashingRepeatedly checking doors, locks, or appliancesRituals to avoid contact with “unlucky” objectsArranging and rearranging objectsUsing prayers or chants to prevent bad things from happeningHoardingHow Often Do OCD and Autism Show Up Together?
Until DSM-5 (2013), OCD was classified as an anxiety disorder. It now sits in its own chapter, “Obsessive-Compulsive and Related Disorders.” Anxiety is one of the most common co-occurring experiences for Autistic people. About 40% of Autistic children and teens meet criteria for at least one anxiety disorder (one 2011 meta-analysis). Across ages, a 2019 meta-analysis estimated OCD in about 9% of Autistic people.
Here are some research findings on co-occurrence:
- The same 2011 meta-analysis found that about 17% of Autistic young people also had OCD.
- The link may run both ways. A population-based study in Denmark found links between OCD and autism within families. Autistic people were about twice as likely to be diagnosed with OCD later in life, and people with OCD were about four times as likely to be diagnosed with autism later on.
- In a UK study of 73 adult outpatients with OCD, 47% scored above the clinical cutoff on the Autism-Spectrum Quotient (AQ), and 27.8% met criteria for autism on clinical interview. None had been diagnosed before. A larger share of people with OCD may be Autistic than we realize.
Where They Overlap (and Where They Differ)
The reasons behind the behaviors differ between the two conditions, but there are several overlapping characteristics:
- People with both conditions can have unusual sensory experiences (one 2015 network analysis).
- Some children with OCD have sensory intolerance as their main symptom, which drives time-consuming rituals (one case series).
- In adults, current and recalled childhood oral and tactile hypersensitivity were linked with OCD symptoms (one 2012 study).
- Unusual sensory interests may be key to understanding the link between autism and OCD, and may point to different pathways to compulsive behavior (sensory-based vs. cognitive-based) (the same network analysis).
- Autistic children in one study showed more obsessive-compulsive traits than non-Autistic peers, especially hoarding, ordering, and repeating.
- OCD rituals can resemble Autistic repetitive behaviors, but the function is different. In OCD, compulsions reduce a distressing thought, fear, or anxiety. For Autistic people, repetitive behavior is more often tied to sensory processing and is a way of self-soothing (Ruzzano and colleagues, 2015).
- Both involve some of the same brain circuits, including the caudate (part of the striatum). In autism, this area is linked to rigid routines and repetitive behaviors (one 2016 study; one 2009 study), and in OCD it is associated with compulsions.
OCD and autism can look similar from the outside, but the reasons behind the behaviors differ. Compulsions ease the distress of obsessions, while Autistic routines and stimming support regulation. And a person can be both Autistic and have OCD.
When Someone Is Autistic and Has OCD
It’s important to know when both are present, because treatment recommendations may differ for Autistic people with OCD. People with both tend to have experiences that are distinct from people who have just one of the conditions. For example:
- Standard CBT for OCD helps Autistic young people, but less than it helps non-Autistic peers. In one case-controlled study, 9% of Autistic young people reached remission, compared with 46% of non-Autistic young people. Autism-adapted CBT shows promise, though outcomes are still modest (one 2020 study; one 2021 study).
- In a large trial, the SSRI citalopram was no better than placebo for repetitive behaviors in Autistic children and caused more side effects.
- Autistic people often do better when CBT is adapted. In one autism-adapted CBT manual for teens, adaptations included building in special interests, visual worksheets, inviting parents into sessions, learning to tell anxiety apart from other emotions, a longer course of treatment (20 sessions instead of 14), and holding some sessions in places where OCD tends to get triggered.
Clinician’s Corner: How to Spot the Difference
- Understand the function of repetitive behavior. Look for a functional relationship between the repetitive behavior and fear. In OCD, there is a direct link between obsessions and compulsions: compulsions are a way of coping with and reducing obsessions.
- Screen for autism. Given how often OCD and autism co-occur, consider routinely screening for autism using the AQ or other screeners.
- Notice how the person takes in information. Do they process bottom-up, starting with details? Do they do better with visual information? These are common Autistic ways of processing.
- Consider the sensory profile, while keeping in mind that people with OCD can also have sensory sensitivities.
- Assess for Criterion A (social communication). For a strengths-based summary of the DSM criteria for autism, see this article.
In OCD, compulsions are a way of reducing obsessions. For Autistic people, repetitive behavior is more often a way to self-soothe.
A Few Closing Thoughts
OCD and autism can look alike from the outside, and many people live with both. Asking what a repetitive behavior is for, whether it eases a feared thought or helps someone regulate, is often the clearest way to tell them apart.
For those of us who are Autistic and live with OCD, having both named matters. It shapes how therapy gets adapted, and it can help us sort out which routines soothe us and which ones are driven by fear. If OCD treatment hasn’t fit well, it may be worth raising autism with your care team.
OCD and Autism FAQs
Can OCD be mistaken for autism?
Yes. Repetitive behaviors, routines, and sensory differences show up in both. The clearest difference is usually the function: OCD compulsions reduce a distressing thought or fear, while Autistic repetitive behaviors more often support sensory regulation and self-soothing.
Can you be Autistic and have OCD?
Yes. In one meta-analysis, about 17% of Autistic children and teens also had OCD. In a UK study of adults with OCD, about 28% met criteria for autism on clinical interview, and none had been diagnosed before.
What is the difference between OCD compulsions and stimming?
Compulsions are driven by obsessions and are done to reduce anxiety or prevent a feared outcome. Stimming and Autistic routines usually support regulation and self-soothing, and aren’t tied to an obsession.
Does CBT work for OCD in Autistic people?
Standard CBT helps, but in one study Autistic young people were less likely to reach remission than non-Autistic peers. Autism-adapted CBT, with visuals, special interests, parent involvement, and a longer course of treatment, shows promise.
Additional Resources
ADHD vs. Autism vs. OCD: how all three overlap, differ, and show up together
ADHD vs. OCD: differences, overlap, and co-occurrence
OCPD vs. Autism: how to spot the differences and avoid misdiagnosis
Autism screeners: AQ, RAADS-R, CAT-Q (camouflaging), RBQ-2A (repetitive behaviors), Aspie Quiz, and the Alexithymia Questionnaire (not an autism screener, but alexithymia is common among Autistic people). More in our autism and ADHD screeners guide
OCD screener: Psych Central OCD quiz
This post contains affiliate links. If you buy through them, we may earn a small commission at no extra cost to you. We only link to things we use or trust.
For kids: Standing Up to OCD Workbook for Kids by Tyson Reuter
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References
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