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Obsessive-Compulsive Disorder (OCD) is often portrayed in popular culture as a disorder centered solely around irrational fears and repetitive rituals. While fear and anxiety are important components of OCD for many individuals, contemporary research increasingly demonstrates that OCD is far more complex than a simple problem of distorted thinking or unreasonable fear (Taylor, 2011). Many individuals with OCD experience significant sensory phenomena, “not-right” feelings, intolerance of uncertainty, and nervous system dysregulation that cannot be fully explained through traditional fear-based models alone (Miguel et al., 2000).

At the same time, OCD frequently co-occurs with neurodevelopmental conditions such as Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD), creating additional complexity for clinicians attempting to determine whether a behaviour should be treated using cognitive behavioural interventions or approached through a neurodivergent-affirming sensory and accommodation framework (Van Ameringen et al., 2014).

OCD Is Not Always Primarily About Fear

Traditional cognitive behavioural models conceptualize OCD as a cycle involving intrusive thoughts, anxiety, compulsions, and temporary relief. In many cases, this framework is highly effective and clinically useful (Abramowitz, McKay, & Storch, 2017). However, growing evidence suggests that OCD symptoms are not always primarily driven by fear or catastrophic beliefs.

Many people with OCD report experiencing intense internal sensations of incompleteness, tension, disgust, or “not-right” experiences that compel repetitive behaviours even in the absence of a clearly articulated fear (Coles et al., 2003). Sensory phenomena are particularly common in tic-related OCD and in individuals with co-occurring neurodevelopmental conditions (Miguel et al., 2000).

For example, an individual may repeatedly adjust clothing because seams feel physically intolerable, rearrange objects because the visual asymmetry creates overwhelming discomfort, or repeat actions until they feel “just right.” In these cases, compulsions may function partly as attempts to regulate sensory distress rather than solely attempts to prevent feared outcomes.

Research on sensory over-responsivity has also demonstrated strong relationships between sensory processing differences and OCD symptom severity (Dar et al., 2012). These findings suggest that OCD cannot always be reduced to irrational cognition alone; sensory and physiological experiences may directly contribute to compulsive behaviour.

Intolerance of Uncertainty and Nervous System Regulation

Intolerance of uncertainty is one of the most well-established features associated with OCD and anxiety disorders (Carleton, 2016). Individuals with OCD often experience extreme distress when situations feel unpredictable, ambiguous, or incomplete.

However, intolerance of uncertainty is also strongly associated with autism and ADHD, particularly in individuals who experience sensory processing differences and chronic nervous system dysregulation (Boulter et al., 2014). Sensory overload may intensify the need for predictability, repetitive routines, and environmental control.

For some individuals, repetitive behaviours may therefore serve multiple simultaneous functions:

• reducing anxiety,
• restoring sensory equilibrium,
• increasing predictability,
• and regulating physiological distress.

This creates important clinical implications. A behaviour that appears compulsive may also function as a legitimate sensory accommodation or self-regulation strategy.

For instance:

• avoiding loud environments may reduce sensory overload rather than represent pathological avoidance,
• maintaining rigid routines may prevent nervous system dysregulation,
• and repetitive movements may provide grounding or sensory organization.

As a result, clinicians must carefully assess whether a behaviour is primarily fear-maintained, sensory-regulatory, or some combination of both.

OCD Commonly Co-Occurs With Autism and ADHD

Research consistently demonstrates elevated rates of OCD among autistic individuals and individuals with ADHD (Van Ameringen et al., 2014). Likewise, many people diagnosed with OCD exhibit autistic traits, executive functioning differences, or sensory processing challenges.

A large population-based study found that individuals with autism were approximately twice as likely to later receive an OCD diagnosis, while individuals with OCD were several times more likely to later receive an autism diagnosis (Meier et al., 2015). Similarly, ADHD and OCD frequently co-occur, particularly in childhood and adolescence (Geller et al., 2007).

This overlap can make differential diagnosis extremely challenging because autism, ADHD, and OCD may all involve:

• repetitive behaviours,
• rigidity,
• sensory sensitivities,
• executive functioning difficulties,
• emotional dysregulation,
• and difficulty tolerating uncertainty.

However, the motivations underlying these behaviours may differ significantly.

For example:

• an autistic individual may depend on routines because predictability reduces sensory and cognitive overload,
• a person with OCD may engage in rituals to neutralize intrusive fears,
• and an individual with ADHD may repeatedly check tasks due to working memory impairments or executive dysfunction.

Importantly, many individuals experience multiple overlapping mechanisms simultaneously.

The Difficulty of Determining Appropriate Treatment Approaches

One of the most difficult aspects of treatment involves determining which behaviours should be addressed through cognitive behavioural interventions such as Exposure and Response Prevention (ERP), and which should instead be supported through accommodations and neurodivergent-affirming care.

ERP remains one of the most evidence-based treatments for OCD and can significantly reduce fear-based compulsions (Abramowitz et al., 2017). However, clinicians increasingly recognize that exposure approaches may require adaptation when working with neurodivergent individuals, particularly those with significant sensory processing differences (Kerns et al., 2016).

This distinction is not always straightforward.

For example:

• Is noise avoidance caused by sensory hypersensitivity or anxiety-driven avoidance?
• Is a rigid bedtime routine a compulsive ritual or a necessary regulation strategy?
• Is repetitive checking driven by intrusive obsessional fear, executive dysfunction, sensory discomfort, or some combination of all three?

Misinterpreting sensory regulation needs as pathological compulsions may lead to invalidating or destabilizing interventions. Forcing sensory exposure without adequate accommodations may increase dysregulation rather than improve functioning. Conversely, assuming all repetitive behaviours are adaptive may result in untreated OCD symptoms continuing to cause severe distress and impairment.

Because of this complexity, many clinicians advocate for integrative approaches that combine evidence-based OCD treatment with neurodivergent-affirming practices.

Toward an Integrative and Neurodivergent-Affirming Framework

Neurodivergent-affirming approaches emphasize understanding behaviours within the broader context of sensory processing, nervous system regulation, communication differences, executive functioning, and lived experience rather than automatically pathologizing repetitive behaviour (Walker, 2021).

This does not require abandoning cognitive behavioural therapy. Instead, it involves carefully differentiating:

• compulsions that are primarily fear-maintained,
• behaviours that are adaptive sensory accommodations,
• and behaviours that contain elements of both.

Adapted treatment approaches may include:

• sensory accommodations,
• predictable therapeutic structure,
• collaborative goal setting,
• visual supports,
• pacing modifications,
• executive functioning support,
• and explicit discussion about the purpose a behaviour serves.

Increasingly, clinicians recognize that effective care requires moving beyond simplistic assumptions about OCD as merely “irrational fear.” OCD may involve deeply embodied sensory experiences, neurodevelopmental overlap, and attempts to regulate overwhelming internal states.

Conclusion

OCD is substantially more complex than common stereotypes suggest. Although intrusive fears and compulsions are central features for many individuals, OCD can also involve sensory processing differences, “not-right” experiences, nervous system dysregulation, and significant overlap with autism and ADHD.

These overlapping experiences make it difficult to determine when behaviours should be reduced through cognitive behavioural interventions and when they should be respected as adaptive neurodivergent accommodations. As research evolves, there is increasing recognition that clinicians must consider the full neurological, sensory, emotional, and environmental context of a person’s experiences rather than relying exclusively on traditional fear-based models of OCD.

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References

Abramowitz, J. S., McKay, D., & Storch, E. A. (2017). The Wiley handbook of obsessive compulsive disorders. Wiley-Blackwell.

Boulter, C., Freeston, M., South, M., & Rodgers, J. (2014). Intolerance of uncertainty as a framework for understanding anxiety in children and adolescents with autism spectrum disorders. Journal of Autism and Developmental Disorders, 44(6), 1391–1402.

Carleton, R. N. (2016). Into the unknown: A review and synthesis of contemporary models involving uncertainty. Journal of Anxiety Disorders, 39, 30–43.

Coles, M. E., Heimberg, R. G., Frost, R. O., & Steketee, G. (2003). “Not just right experiences”: Perfectionism, obsessive-compulsive features and general psychopathology. Behaviour Research and Therapy, 41(6), 681–700.

Dar, R., Kahn, D. T., & Carmeli, R. (2012). The relationship between sensory processing, childhood rituals and obsessive-compulsive symptoms. Journal of Behavior Therapy and Experimental Psychiatry, 43(1), 679–684.

Geller, D. A., Petty, C., Vivas, F., Johnson, J., Pauls, D., & Biederman, J. (2007). Examining the relationship between obsessive-compulsive disorder and attention-deficit/hyperactivity disorder in children and adolescents. Journal of Psychiatric Research, 41(3–4), 316–323.

Kerns, C. M., Kendall, P. C., Zickgraf, H., Franklin, M. E., Miller, J., & Herrington, J. (2016). Not to be overshadowed or overlooked: Functional impairments associated with comorbid anxiety disorders in youth with ASD. Behavior Therapy, 46(1), 29–39.

Meier, S. M., Petersen, L., Schendel, D. E., Mattheisen, M., Mortensen, P. B., & Mors, O. (2015). Obsessive-compulsive disorder and autism spectrum disorders: Longitudinal and offspring risk. PLoS ONE, 10(11), e0141703.

Miguel, E. C., do Rosário-Campos, M. C., Prado, H. S., et al. (2000). Sensory phenomena in obsessive-compulsive disorder and Tourette’s disorder. Journal of Clinical Psychiatry, 61(2), 150–156.

Taylor, S. (2011). Clinician’s guide to PTSD: A cognitive-behavioral approach. Guilford Press.

Van Ameringen, M., Patterson, B., & Simpson, W. (2014). DSM-5 obsessive-compulsive and related disorders: Clinical implications of new criteria. Depression and Anxiety, 31(6), 487–493.

Walker, N. (2021). Neuroqueer Heresies. Autonomous Press.