OCD and Autism – Where They Co-Occur and Overlap

Defining Autism and OCD

Autism is a lifelong neurological difference that affects the way one person experiences the world. It is characterised by differences in social interaction and communication, as well as unique responses to sensory input. In the UK, autism is formally diagnosed through a multidisciplinary assessment following the National Institute for Health and Care Excellence (NICE) guidelines.

On the other hand, Obsessive-Compulsive Disorder (OCD) is a mental health condition characterised by the presence of intrusive thoughts (obsessions), repetitive behaviours or mental acts performed to reduce distress (compulsions). OCD can be severely impairing and is typically diagnosed using structured psychological or psychiatric assessments.

Research from UK sources, such as King’s College London and NHS Trusts, estimates that up to 25% of autistic children and young people meet the criteria for OCD. However, the nature of co-occurrence is complex. For example, behaviours such as lining up toys, strict routines, or repeated questioning may be seen in both, but for different reasons.

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There are multiple diagnostic challenges that autistic people with OCD face when it comes to conducting a valid assessment. We will be discussing the most common:

1. Symptom Overlap – Autistic people indulge in behaviours and routines that provide comfort, predictability, or sensory regulation. These behaviours can superficially resemble the compulsions seen in OCD. However, a critical distinction lies in the intent and emotional experience: Autistic routines are typically egosyntonic (aligned with the person’s preferences). At the same time, OCD compulsions are often egodystonic (experienced as distressing or intrusive). Distinguishing between these requires a nuanced, autism-informed clinical assessment.
2. Diagnostic Overshadowing – A common risk in diagnostic practice is that obsessive or compulsive symptoms are mistakenly attributed to autism alone, a phenomenon known as diagnostic overshadowing. This can lead to underdiagnosis or delayed diagnosis of OCD in autistic people, particularly in children who already present with rigid behaviours.
3. Assessment Tool Limitations – Standardised assessment tools for OCD may not adequately differentiate between autistic traits and OCD symptoms. Similarly, autism diagnostic tools may not fully capture the presence of obsessive-compulsive behaviours unless they are unusually severe or distressing. According to clinicians from services like SCAAND (South London and Maudsley NHS Foundation Trust), careful clinical interviews, collateral history, and adapted tools are essential.
4. Divergent Pathways – In the UK, autism is typically assessed by neurodevelopmental teams, while OCD may be referred to CAMHS or adult mental health services. The lack of integrated diagnostic pathways can result in fragmented care and missed opportunities for holistic support.

Accurate diagnosis is essential for people to experience improvement in the quality of life, reduce stress and ensure that support services align with the person’s neurodevelopmental and mental health profile. To take on these challenges and achieve a better tomorrow, UK services increasingly recommend:

• Multidisciplinary assessment involving autism and mental health specialists
• Use of adapted Cognitive Behavioural Therapy (CBT) for autistic people with OCD
• Enhanced training for the care teams in differentiating between RRBs and compulsions
• Involving families and support networks in observation and care planning

Read more about what our occupational therapist says about the key factors in adequately assessing and evaluating autistic people.

Similarities Between OCD and Autism

Understanding the shared traits and behavioural overlaps between OCD and autism is prevalent because, without this insight, people’s chances of experiencing misdiagnosis, delayed support, or interventions that don’t fully meet their needs are high. We can move toward more accurate assessments and compassionate care by looking beyond the surface and exploring the emotional purpose behind behaviours, whether to relieve distress or create a sense of order.

In this section, we explore the key similarities between OCD and autism and why they matter in diagnosis, support planning, and day-to-day understanding.

Repetitive Behaviours and Routines

People with either OCD or autism may engage in repetitive actions or routines. While these may look similar on the surface, the underlying purpose and emotional impact are often different:

• In autism, routines and autistic stemming can offer comfort, predictability, or sensory regulation. These behaviours may feel natural, purposeful, or enjoyable to the person.
• In OCD, repetitive behaviours (or compulsions) usually occur in response to distressing or intrusive thoughts (obsessions). For example, someone may feel a strong urge to check something repeatedly to reduce anxiety or prevent a feared outcome. These behaviours are often experienced as unwanted or exhausting.

Understanding whether a behaviour is self-directed and affirming, or distress-driven and unwanted, helps to identify its origin and provide the right support.

Need for Predictability and Control

Many autistic people and people living with OCD value structure and predictability in their daily lives. However, the reasons for this preference may differ:

• Autistic people may feel more at ease and in control when life is structured or predictable. This can help reduce overwhelm and support regulation, especially in environments that are fast-paced, unfamiliar, or sensory-rich.
• People with OCD may develop rituals or strict rules as a way to cope with anxiety caused by intrusive thoughts. These behaviours may not be about the routine itself, but about trying to prevent something bad from happening or to feel safe.

Sensory Processing Issues

Autistic people commonly experience sensory processing differences, and they can also be a feature of OCD:

• Autistic people may experience heightened or reduced sensitivity to things like sound, light, textures, or movement. These differences are part of their unique neurodevelopment and may shape preferences and daily routines, such as wearing particular clothes or avoiding specific environments.
• People with OCD may develop sensitivities related to feelings of discomfort, contamination, or incompleteness. For example, they may engage in repeated washing or cleaning even when no visible dirt is present, due to a powerful internal sense that something feels “off.”

Key Differences Between OCD and Autism

Although autism and Obsessive-Compulsive Disorder (OCD) may share some outward behaviours, they are fundamentally different in their underlying causes, emotional experiences, and the kind of support people may need.

Nature and Purpose of Repetitive Behaviours

The function or the emotional experience behind the repetitive behaviour is key, and sometimes it differs.

In autism, autistic stimming as a self-stimulatory behaviour may include movements like repeating sounds or arranging objects. Autistic stimming often soothes and emotionally regulates the autistic person; it expresses joy, manages sensory input, or focuses attention. It feels comfortable and purposeful to the person.

In OCD, repetitive behaviours (or compulsions) usually occur in response to distressing or intrusive thoughts (obsessions). They are typically performed to reduce anxiety caused by unwanted, intrusive thoughts (obsessions), driven by fear or a perceived need to prevent harm (e.g. checking locks repeatedly) and are often experienced as exhausting.

✅ Key difference: Autistic stimming is usually self-affirming and enjoyable. OCD compulsions are anxiety-driven and distressing.

Social Communication vs. Anxiety-Driven Symptoms

Autistic people may experience differences in how they interact, communicate, and understand others. This can include:

• Difficulty with social cues, sarcasm, or indirect communication
• A preference for literal language
• Differences in how relationships are formed or expressed

These differences are part of someone’s neurodevelopmental profile, not signs of mental illness or emotional disturbance.

In OCD, social difficulties are typically not present in the same way. Instead, social withdrawal or avoidance may happen as a secondary effect of anxiety. For example, a person may avoid social contact due to fears of contamination, intrusive thoughts about causing harm, or fears of saying something inappropriate.

✅ Key difference: Autism involves lifelong social communication differences. In OCD, social avoidance tends to be anxiety-related and situational.

Emotional and Cognitive Processing

Autistic people may experience:

• Heightened or reduced sensitivity to emotions (their own or others’)
• A need for extra processing time or alternative ways to express emotions
• Cognitive strengths like deep focus, visual thinking, or pattern recognition
• Challenges with uncertainty or sensory overwhelm

These are part of the person’s natural cognitive style and may influence how they interact with the world and manage emotions.

People with OCD often describe:

• Persistent, distressing thoughts that are unwanted and intrusive
• High levels of doubt or fear (e.g. “What if I made a mistake?”)
• Difficulties “letting go” of thoughts or uncertainty
• A drive for mental or emotional relief through rituals or reassurance-seeking

OCD is typically associated with intense emotional distress caused by the content of obsessive thoughts, rather than how the brain processes external stimuli.

✅ Key difference: Emotional differences in autism are part of a person’s neurodivergent profile. In OCD, emotional distress is more linked to obsessional thinking and fear cycles.

Challenges Faced When Both Co-occur

When autism and Obsessive-Compulsive Disorder (OCD) are both part of a person’s experience, the overlap can create a complex and often misunderstood picture. While each condition brings unique strengths and challenges, their co-occurrence can intensify emotional, social, and sensory difficulties. This may affect how a person manages daily routines, relationships, learning, or support.

Increased Anxiety and Emotional Dysregulation

Living with both autism and OCD can lead to heightened levels of anxiety, which may affect emotional well-being and day-to-day functioning. People with OCD may already experience intense and distressing intrusive thoughts. When combined with autism, where routines, predictability, and sensory regulation are central to coping, disruption or uncertainty can feel even more overwhelming. Autistic people may already experience emotional regulation differences, including delayed emotional processing, shutdowns, or meltdowns. When OCD is also present, this emotional distress can be amplified by compulsive urges or fears related to obsessional thinking (e.g., needing to complete rituals “just right”).

• The cognitive effort involved in managing both autism-related sensory needs and OCD-related compulsions can be exhausting, leaving little space for rest, spontaneity, or social engagement.

Impact: The emotional load of the co-occurrence of both can lead to burnout, withdrawal, and difficulty participating in everyday life without tailored, compassionate support.

Social Challenges

Autistic people may experience differences in understanding social cues, interpreting nonspeaking communication, or forming and maintaining relationships. Social interactions can be draining or confusing, particularly in fast-paced or unpredictable environments.

People with OCD might withdraw socially due to anxiety, embarrassment, or fear of acting on intrusive thoughts. For example, someone may avoid group settings due to a fear of contamination, or repeated checking behaviours may interfere with peer relationships.

• When both conditions co-occur, there may be increased feelings of isolation or difficulty being understood by others. The unique combination of social differences and obsessive fears may make it hard to explain one’s needs, ask for help, or feel included.

Impact: These social challenges can affect confidence, access to education or work, and emotional well-being, especially without environments that promote understanding, inclusion, and neurodiversity acceptance.

Sensory Sensitivities

Sensory processing differences are a core feature of autism and may also interact with OCD symptoms. Autistic people may experience heightened or reduced sensitivity to sound, light, textures, smells, or movement. This can influence behaviour, daily routines, and comfort in certain environments. For someone with co-occurring OCD, these sensory differences may become tied into compulsions or avoidance behaviours. For example:

• A strong aversion to a texture might trigger obsessive thoughts about contamination.
• Sensory discomfort could increase emotional distress, leading to more frequent compulsions as a way to self-soothe.
• Some people may develop rituals linked to sensory input, such as repeated washing or checking, not only due to obsessional thinking but also to manage uncomfortable sensory experiences.

Impact: Sensory overload may trigger or intensify OCD-related behaviours, and vice versa. This can limit a person’s ability to engage in daily tasks, attend school or work, or feel safe in public spaces without proper support.

Read more about how autistic people can manage sensory overload.

Tailored Support Strategies

Because autism and OCD can interact in very challenging ways (emotionally, behaviourally, and cognitively), strategies must be adaptable, collaborative, and respectful of neurodiversity. The goal is not to remove a person’s coping tools or identity-based behaviours, but to reduce distress, build self-understanding, and foster wellbeing.

Here are some outcome-based and inclusive strategies that can help:

1. Autism-Informed Support Approaches. Traditional therapeutic models like CBT can be helpful, but they often need autism-informed adaptations to be meaningful and effective. Autism-informed support focuses on meeting the person where they are, acknowledging sensory needs, communication preferences, and the person’s way of experiencing the world.

Key autism-informed support strategies include:

• Using visual supports (timelines, emotion charts, task breakdowns)
• Incorporating special interests to build trust and motivation
• Respecting alternative communication styles (e.g., nonspeaking, AAC)
• Avoiding forced eye contact or neurotypical social demands
• Focusing on distress reduction, not on eliminating harmless behaviours like stimming
• Providing extra processing time during discussions or problem-solving

This approach centres on co-regulation, understanding, and predictability, allowing individuals to explore and manage OCD-related distress in a way that feels safe and empowering.

2. Creating Predictable, Low-Anxiety Environments. Strategies include visual schedules, consistent routines and clear expectations, low-arousal environments, and gradual preparation for changes (social stories, countdowns). These approaches help reduce anxiety that may trigger compulsive behaviours or sensory overload.
3. Strengthening Emotional Regulation Skills. Support may involve identifying early signs of emotional dysregulation, using co-regulation techniques with a parent or a support worker, introducing sensory-based calming strategies like movement breaks and calming visuals, and incorporating mindfulness, breathing, or grounding techniques in an autism-friendly format.

Home Care and Support for Autism and OCD with Leaf Complex Care

By focusing on lived experience, intent, and impact, we can ensure that care is respectful, tailored, and inclusive of each person’s needs and identity.

We increasingly recognise the need for integrated, personalised approaches through the Capable Environments model of support. Without this, people may be misunderstood, misdiagnosed, or left to overlapping challenges without the necessary tools. Therefore, our support focuses on:

• Reducing anxiety and emotional distress through adapted interventions (autism-informed support)
• Supporting communication, social connection, and understanding
• Listening to the lived experiences of those affected and involving them in planning their own care
• Collaborative care and multidisciplinary team support
• Providing trauma-informed support, especially where OCD has led to distress, isolation, or school/work avoidance

People want to gain greater autonomy and self-understanding, but do we set the right foundation for people to bloom? Well, our care teams do, and it encourages supported people to communicate their needs in their own way, reduce behaviours of concern, use their strengths and interests to support recovery and develop a positive identity rooted in acceptance and confidence.

Today, we share Rylee’s care journey with you.

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