Obsessive–compulsive disorder (OCD) is one of the most common and impairing co-occurring conditions in autistic individuals, yet it is frequently under-recognised and undertreated. This clinical perspective examines the challenges of recognising, diagnosing, and managing OCD in autism. We discuss the overlap and important distinctions between autistic repetitive behaviours and OCD compulsions, highlighting the need for careful differential diagnosis to ensure that treatable OCD is identified without pathologising core autistic characteristics. We review the limited clinical trial evidence on autism-adapted cognitive behavioural therapy (CBT) for OCD, arguing that the scarcity of treatment trials is likely to reflect a lack of research rather than a lack of efficacy. We also consider barriers to accessing specialist care and discuss the potential of therapist-supported internet-delivered CBT to expand access to evidence-based treatment. Finally, we outline priorities for clinical practice and research, including improving recognition of OCD in autistic people, increasing their inclusion in treatment trials, and developing accessible, autism-adapted interventions.
Anxiety disorders are exceedingly common in autistic individuals, and obsessive–compulsive disorder (OCD) is among the most common and impairing. At least 10% of autistic individuals meet diagnostic criteria for OCD, and a similar proportion of individuals with OCD have co-occurring autism.3 Yet OCD often goes unrecognised and untreated in autistic people, causing unnecessary suffering. First, it can be difficult to establish an accurate differential diagnosis. Second, even when OCD is correctly identified and diagnosed, the clinical management of this comorbidity can be challenging, often requiring access to specialist services that are not always available. In this clinical perspective, we examine these challenges and outline practical approaches to improving the recognition, diagnosis, and treatment of OCD in autistic individuals.
Autism is characterised by differences in social communication and the presence of restricted or repetitive patterns of behaviour. These behaviours can include routines, rituals, and intense interests. At first glance, they may resemble the compulsions seen in OCD. However, there are important differences. In OCD, compulsions are usually performed to reduce anxiety and discomfort associated with intrusive thoughts, fears, or feelings of incompleteness. The behaviour is typically experienced as unwanted or excessive, even if the person feels unable to resist it. In contrast, repetitive behaviours in autism are not typically driven by intrusive thoughts or fears and may be experienced as neutral or even enjoyable.11 They may serve functions such as regulating sensory input, providing predictability, or expressing interest in a preferred topic.4,5,9
When OCD is present, the disorder appears broadly similar to OCD in non-autistic populations in terms of the types of obsessions and compulsions reported.8,11 Importantly, autistic individuals with OCD can experience the same levels of distress and impairment as other patients with the disorder.11 At the same time, autism often shapes the content and expression of OCD symptoms, making them highly idiosyncratic. Obsessions and compulsions may become intertwined with an individual's circumscribed interests, sensory sensitivities, preference for predictability, or rigid adherence to routines, resulting in symptom presentations that differ somewhat from those typically seen in non-autistic populations.
In some cases, the clinical boundary between the two conditions can be difficult to establish. Differential diagnosis is important because it determines whether OCD-specific treatment is indicated. Accurate delineation is also important to ensure that the focus of intervention is legitimate and does not include attempts to change characteristics of autism that are beyond an individual's control and form an important part of who they are. Autistic individuals may have difficulty describing internal experiences such as intrusive thoughts. Communication differences and differences in emotional self-awareness may make it harder to identify the anxiety or other emotions, such as disgust and feelings of incompleteness, that drive compulsions. Clinicians who are unfamiliar with OCD may assume that repetitive behaviour is part of the developmental condition rather than a separate, treatable disorder. As a result, OCD symptoms may be overlooked.
There are instances in which even expert clinicians struggle to differentiate these phenomena. The most common example involves symmetry obsessions and ordering compulsions, which may manifest without specific fears or intrusive thoughts. These OCD symptoms are associated with feelings of incompleteness or “not just right” experiences, making them difficult to distinguish from the preference for sameness in autism. In these instances, one pragmatic approach is to experiment collaboratively with the autistic person in the clinic to determine what happens when the compulsion or routine is interrupted, while closely monitoring distress and behavioural change. If the behaviour is driven by OCD-related mechanisms, anxiety should eventually decrease as the individual learns to refrain from the compulsive behaviour. In contrast, when the behaviour reflects autistic insistence on sameness, attempts to block the behaviour may lead to frustration, distress, or anger without the characteristic reduction in anxiety seen in OCD.
Although OCD is often missed in children and adolescents with autism, the opposite problem can also occur. In adult psychiatric services, autism itself may go unrecognised. Some autistic adults present with longstanding anxiety, social difficulties, or rigid behavioural patterns and may receive alternative diagnoses, including personality disorders. This is unhelpful. If autism is missed, clinicians may overlook the need to adapt treatment approaches to suit the individual's needs. Careful assessment is therefore required to determine whether repetitive behaviours reflect autism, OCD, or both.
The first-line psychological therapy for OCD in neurotypical people is cognitive behavioural therapy (CBT) incorporating exposure and response prevention (ERP). CBT is a highly structured, goal-oriented, and skills-based intervention that emphasises predictable session formats, explicit treatment rationales, and gradual behavioural change. These characteristics make it well suited for adaptation to the cognitive, communication, and sensory needs of autistic children and adults.13 Indeed, adapted CBT has been shown to be effective in treating anxiety in autistic young people.15 Unfortunately, OCD treatment trials frequently exclude individuals with autism, often to reduce heterogeneity in study samples. Consequently, relatively little is known about how well standard treatments work in this group or how they might best be adapted. In the only randomised controlled trial to date, 46 autistic adolescents and adults with OCD were randomised to either autism-adapted CBT for OCD or anxiety management, a plausible active control treatment.12 Both groups improved, with no statistically significant difference between them, although a higher proportion of participants were classified as responders in the CBT group.12 However, this trial was likely underpowered to demonstrate superiority.
The scarcity of trials does not imply that treatment is ineffective. Rather, it reflects the limited attention this population has received in OCD research. Addressing this gap will require larger and more inclusive trials. First, autistic individuals should no longer be routinely excluded from OCD trials, so that the generalisability of treatment effects to all people with OCD can be improved. Second, adequately powered trials are urgently needed to establish more firmly the efficacy of autism-adapted interventions for OCD in autistic individuals.
Access to treatment is a different kind of challenge. Treating OCD in some autistic people requires specialist clinical knowledge and experience. Adapting and delivering effective CBT in this population requires expertise in both autism and OCD, persistence, and close collaboration with patients and families. In most parts of the world, such expertise is concentrated in a small number of specialised clinics or among individual clinicians who have developed specific expertise. As a result, autistic individuals with OCD may face long waits and limited or no access to appropriate care.7,10 Digital approaches could help address this problem. Internet-delivered CBT (ICBT) programmes have been successfully developed for neurotypical individuals with OCD.1,2,6 These programmes typically combine online modules with therapist support delivered through messaging or video calls. Digital formats may offer particular advantages for autistic individuals. Online materials can incorporate visual explanations and structured exercises. Written content can be reviewed repeatedly, which may support learning. Some individuals may also find it easier to engage with treatment in a predictable online environment than in face-to-face sessions.
In a recent feasibility study conducted in Sweden, 22 autistic young people with OCD, aged 7–17 years, were treated with a therapist-supported ICBT programme specifically developed for this population.14 For benchmarking purposes, data from 52 young people with autism and OCD receiving in-person CBT at the same specialist OCD clinic were explored. Both groups showed clinically significant improvements from baseline to the 3-month follow-up, the primary endpoint, on the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS). At the 3-month follow-up, response rates were 61% for the ICBT group and 70% for the in-person CBT group. The average therapist treatment time in the ICBT group was 3h 15min per patient for the entire treatment. By contrast, the corresponding treatment time for the benchmark sample was approximately 28 therapy hours per patient.14 Thus, preliminary evidence suggests that it may be possible to treat this complex group successfully using a digital approach in a highly cost-effective manner, although this requires confirmation in a controlled trial. A large multicentre randomised controlled trial of this intervention is currently ongoing (ClinicalTrials.gov identifier: NCT06582225). Digital interventions are unlikely to replace specialist care for all patients, particularly those with severe symptoms. However, they could expand access to evidence-based treatment and reduce the burden on limited specialist services.
In conclusion, OCD is common, impairing, and potentially treatable in autistic people. Yet many individuals do not receive appropriate care because symptoms are overlooked or misinterpreted. Improving outcomes will require better recognition of OCD in autistic populations, greater inclusion of autistic individuals in treatment research, and wider access to adapted interventions. These goals are achievable. The treatments used for OCD already exist; the task now is to ensure that they are tested, adapted, and delivered in ways that meet the needs of autistic people.
Declaration of generative AI and AI-assisted technologies in the writing processDuring the preparation of this work, the authors used ChatGPT to improve parts of the text. The authors reviewed and edited the output as needed and take full responsibility for the content of the published article.
Conflicts of interestProf. Mataix-Cols is an associate editor of the Spanish Journal of Psychiatry and Mental Health. He receives royalties for contributing articles to UpToDate, Wolters Kluwer Health, and is a part owner of Scandinavian E-Health AB, all outside the submitted work. All other authors report no potential conflicts of interest.
None declared.
