The DSM-5 (American Psychiatric Association, 2015) separates Obsessive Compulsive Disorder (OCD) from anxiety disorders, classifying it under the new category as Obsessive-Compulsive Spectrum Disorders (OCRDs), together with two newly defined disorders with obsessive-compulsive features. These are hoarding disorder and excoriation (skin-picking) disorder. Included in the new OCRD category are also body dysmorphic disorder (previously classified as a Somatoform Disorder) and trichotillomania (hair-pulling, previously classified as an Impulse Control Disorder Not Elsewhere Classified). By categorically separating OCD from other forms of anxiety disorder, the DSM-5 recognises that it is unique, and that its neurological and psychological underpinnings are different from that of anxiety disorders.Hence, the treatment of OCD is also different and the neuroanatomical target of therapy should also be different from that of anxiety disorders.The Centers for Disease Control and Prevention (CDC), studies in Asia, Europe, and North America have identified individuals with ASD with an average prevalence of about 1% (CDC, 2015), hence, Autism Spectrum Disorders (ASD) are among the most common neurodevelopmental disorders in the world. Although ASDs are typically diagnosed in early childhood (Di-Cicco-Bloom et al., 2006), there is no specific genetic test or clinical procedure for diagnosis. Diagnosis is based mainly on the following: impairments related to social interaction, communication, as well as restricted and repetitive behavior (American Psychiatric Association, 2015). In addition to impairments in these core symptom areas, many individuals with ASD also have impaired cognitive skills, atypical sensory behaviors, or other complex medical and psychiatric symptoms and conditions, such as seizure disorders, motor impairments, hyperactivity, anxiety, and self-injury/aggression.

Research has revealed that ASD shares similar genetic roots with obsessive-compulsive disorder, and attention deficit hyperactivity disorder (Jacob, Landeros-Weisenberger, & Leckman, 2009). All three conditions share some common features and in terms of similarity in brain architecture, it has been found that there are disruptions in the structure of the corpus callosum in all three conditions. The corpus callosum is the bundle of nerve fibres that connect the brain’s left and right hemispheres.

The purpose of this paper is to examine the neurobiology of OCD, and how the similarities in disruptions of the brain structures between OCD and ASD increases the risk of developing the comorbidity of OCD in teenagers with high-functioning ASD. This paper also explores the prognosis of interventions in individuals diagnosed with both conditions of OCD and ASD, and the applications of interpersonal neurobiology in the treatment of the conditions.

The Neurobiology of Obssessive-Compulsive Disorder and Autism Spectrum Disorder

To have a clear understanding of OCD, and how the disorder affects behaviour, one must first recognize that obsessions and compulsions are two separate manifestations of an illness that have similar biological roots. The DSM-5 defines obsessions as “recurrent and persistent thoughts, urges, or images that are experienced as intrusive or unwanted,” and compulsions are “repetitive behaviours or mental acts that an individual feel driven to perform in response to an obsession or according to rules that must be applied rigidly” (American Psychiatric Association, 2015). Compulsions are the outward manifestations of the hidden obsessive thoughts. They could be likened to the tip of an iceberg, whereas obsessions are the part of the ice berg that is hidden beneath from the surface. Hence, when an individual is not acting out the compulsion, it does not necessarily mean the obsessions are also gone. Per research, obsessions are more resistant to treatment than compulsions and are the source of profound distress in patients.

Current perspectives on the neuroscience of OCD trace the root of the problem to disruptions in the communication between three core brain structures: the cortex, striatum and thalamus, also known as the cortico-striato-thalamic pathways (Jacob, Landeros-Weisenberger, & Leckman, 2009). A breakdown in the proper transmission of information in the pathways, which may also be caused by a chemical imbalance in the pathways, explains why individuals with OCD are stuck in the repetitive loops of thoughts and behaviour. Further research carried out by has also found that white mattertracts in the brain might be affected in OCD. Unlike grey matter, which is largely made up of the cell bodies of neurons, white matter consists mostly of myelinated axons. By examining the brain matter of both OCD and non-OCD patients, they found that there are widespread abnormalities in the white matter of the former, as compared to the latter (Meier et al., 2015).

Aberrations were frequently found in the regions of the corpus callosum and cingulum. The corpus collosum connects the left and right hemispheres of the brain, and the cingulum is the fibre bundle that connects the primary structures of the limbic system, which includes theamygdala,hippocampus, thalamus,hypothalamus, basal ganglia, and cingulate gyrus. Besides reported abnormalities in the cortico-striato-thalamic pathways typically associated with OCD, there are also reports of abnormalities beyond them (Meier et al., 2015). These findings reinforced the perspective that OCD is a result of disintegration within the physical brain system, leading to faulty communications between different brain structures.

For the physical brain, integration is important as it is the basic process that links up the differentiated parts of a system to facilitate in promoting psychological and emotional well-being. These integrated linkages enable individuals to perform more intricate functions such as insight, empathy, intuition, and morality. Integration is essential for maintaining FACES in the neurological system—flexible, adaptive, coherent, energized and stable (Siegel, 2012). Dr. Siegel (2012) uses the river of integration metaphor to explain that if there is deviation from integration, that is represented by the smooth-flowing river in the centre, to the river-banks on either side, this would lead to chaos or rigidity or both, as represented by the river-banks. From this visual metaphor, the central implication is that like a river that naturally flows downstream, complex systems also have a natural compulsion towards integration. Therefore, when the brain and relationships are well integrated, it would lead to healthy minds. However, if there is impaired integration, it would lead to chaos and rigidity. As in the case of individuals with OCD, the breakdown in the communications between the physical brain structures impairs integration, hence, chaos in the mind and disintegration in relationships.

Similar patterns of disintegration are also observed in the brain patterns of individuals with ASD (Minshew & Williams, 2007). ASD, like OCD, is also a neurobiological disorder of connectivity. For ASD, one similar behavioural feature it shares with OCD is that of restricted and repetitive behaviours. In depth studies into the topic has shown that restricted and repetitive behaviours often observed in individuals with ASD, are also caused by abnormalities in the cortico-striato-thalamic pathways. Restricted and repetitive behaviours are the result of disruptions to any one of the three macro circuits within the cortico-striato-thalamic loops. Problems with communication between the pathways connecting the three brain areas: thecortex,striatum, andthalamus(i.e. cortico-striato-thalamic pathways), will lead to an imbalance within these pathways, hence, may cause individuals with OCD or ASD to get stuck in repetitive loops of thought and behaviour (Minshew & Williams, 2007).

Besides connectivity problems between different brain structures that explain how and why individuals are trapped in repetitive loops of thought and behaviour, research has also shown that several neurotransmitters are responsible for repetitive and rigid behaviour (Minshew & Williams, 2007). One of the key neurotransmitter identified is Serotonin. Serotonin is responsible for proper regulation of memory, sensory perception, mood, learning and behaviour. Therefore, when there is an upset in the Serotonin level in the brain, it leads to abnormalities in behaviour and emotions—disintegration in proper function of the brain system results in chaos and rigidity. Similarly, dysregulation of dopamine, a neurotransmitter primarily responsible for attention and focus, relaying and processing of information, will result in abnormal behaviour and emotions—low dopamine levels impair attention and focus, whereas high dopamine levels increase sensory perception and sensitivity, causing the mind to race. Consequently, it leads to an overload on the brain’s ability to process. GABA (gamma-aminobutyric acid) is a neurotransmitter that occurs naturally in the brain, and is responsible for the regulation of brain activity. Unlike serotonin or dopamine, which are excitatory neurotransmitters, GABA is inhibitory and slows down neuronal firing. Hence, deficient levels of GABA or problematic GABA receptors contribute to the excitatory elements of ASD and OCD, leading to increase anxiety levels (Jacob, Landeros-Weisenberger, & Leckman, 2009).

Interaction of OCD and ASD

The rate for comorbid diagnoses of OCD in patients with ASD differed from 1.5% to 81%. Studies focusing on children with Asperger’s Syndrome found that these children may experience level of impairment from OCD symptoms as children diagnosed with OCD alone. OCD symptoms and behaviour also contribute significantly to the distress faced by adults with ASD (Stone & Chen, 2015). Individuals with ASD share common traits with OCD patients, like ritualistic and avoidance behaviours, the inflexibility of thoughts, and repetitive thoughts. On the other hand, research has shown that individuals with OCD also present with ASD traits. It is estimated about 3% to 7% of patients with OCD also meet the criteria for mild to moderate ASD (Stone & Chen, 2015).

An intricate relationship exists between brain, mind and body, and is illustrated in the triangle of well-being (Siegel, 2012). The physical brain and nervous system allows for energy and information flow throughout our beings. The brain receives the electrical signals that travel through the nervous system, decodes the signals to give them meaning, and responds by releasing neurochemicals and dispatching electrical signals. In this consistent pattern of receiving, decoding and then dispatching new signals, the brain regulates the body, controls movement and influences emotions (Siegel, 2012).

However, for the individual diagnosed with OCD, the disintegration of the cortico-strito-thalamic loop disrupts the dispatching of electrical signals and release of neurochemicals in the body, contributing further to the breakdown of the brain system and the mind. The brain’s function as a social organ is disrupted, rendering it impossible to promote interaction with other brains. The mirror neurons in the brain gives it the capacity to develop empathy and insight (Llosa, 2011). However, for individuals with OCD and ASD, the inability to build interpersonal relationships that are attuned, would mean the inability to encourage the growth of integrative fibres in the brain. This neural integration is important and essential for it enables the embodied brain to function effectively, as well as the development of a coherent and well-balanced mind. Most importantly, when neurons are activated, the brain makes meaning of experiences. It follows that repeated activation creates, strengthens and maintains connections (Siegel, 2012)— “neurons which fire together wire together.” The repeated obsessive thoughts are reinforced if left uncontested, as the thoughts get embedded in the mind with the continuous activation of neurons. The rigidity of the ASD mind, due to connectivity problems and faulty system of neurotransmitters strengthens the resilience of obsessive thoughts, making them even harder to eradicate.

I have encountered a client with ASD, whom I would address as M, who struggles with obsessive thoughts that appear to be both irrational and delusional to the logical and rational individual. The thoughts started as a simple curiosity about little children and their physiological development. As M was brought up to respect privacy and to understand that asking questions about sexual development was inappropriate, it was a struggle within herself to have questions about the same topic that was taboo in her culture. The thoughts soon spiralled out of hand and generated irrational ideas that she could be a paedophile because she felt that she was not normal to be curious about sexuality and sexual development. As she struggles with her own curiosities, they conflicted with the rational side of M, that was also sending signals to her brain that such thoughts were inappropriate. The conflict between the two sets of thoughts increases anxiety in M. Compulsive acts of frequently washing her hands and prolong washing of her body started to surface. Prior to the obsession with the thoughts, there have been reports of compulsive acts of hand washing in M. But these acts were a result of her ASD, and they were more ritualistic and repetitive than compulsions driven by obsessions. During our conversations, M would share how she was compelled to stay in the baths for hours or wash herself repetitively because she had wanted to “wash out” her inappropriate thoughts. Parents also reported of M breaking down at home and calling herself a paedophile and should be institutionalised.

Her obsessions also led her to resist going to school or any places that had little children around. She was afraid she would be triggered and harm the children and she became excessively anxious as she sought to hide from small children. The physiological stress produced reduces further efficient cognitive functioning and mental flexibility. As her ASD condition would mean compromise to her executive function and flexibility in thoughts, the OCD only served to enhance the weaknesses and strengthen negative emotional tone. As the brain consistently sends signals of danger to her nervous system, there have been occasions where she enters “freeze” mode to cope with the intense stress and anxiety experienced. Although she is receiving cognitive behavioural therapy, improvements are small and her emotions continue to fluctuate daily. Further research also shows that individuals with OCD, particularly those with co-morbid ASD responded less well to cognitive behavioural therapy than those who did not have ASD (Murray, Jassi, Mataix-Cols, Barrow, & Krebs, 2015).

In retrospect, CBT did contribute to improvement in her condition as occurrences of the compulsions might have reduced in that the compulsion to wash of hands continuously have been reduced, and she is showing more effort to overcome her obsessive thoughts. One of the methods employed was the externalisation of her thoughts processes, and helping her to understand what was happening in her brain as she struggles with the obsessions. In being able to name the emotions and the problem, the aim is to work towards taming it (Siegel, 2012). Nevertheless, in days when she is less successful in regulating her thoughts, she continues to be trapped in the struggle and becomes dysfunctional. As the mind is shaped via interactions with others because of the exchange of energy and information that occurs, her constant interactions within herself, and repetitive thought patterns reinforces certain ideas that seems to be leading to new obsessions. After 3 years of intensive treatment with CBT and exposure therapy, M learnt to manage her thoughts and eventually overcame the irrational thoughts. She started to accept that there were problems with her fundamental beliefs and not her curiosity, she was more opened to ask questions and when she started to change her belief system and re-evaluate her thoughts, her obsessions started to fade. She called me one day and happily told me when she saw this whole bunch of children at the playground, she was no longer triggered. From that point, it was onto the path of recovery. Today, M is a highly functional young lady who is working towards becoming a health professional herself, so she can help others.


Existing literature on the topic of ASD and OCD, explains the overlap of symptoms, and present the neurobiological evidence to explain why these overlapping takes place. However, there is still little writing on how the coexistence of both conditions may result in the impairment of cognitive abilities. Further research would be needed to explore the possible cognitive impairments because of ASD-OCD comorbidity.

A better understanding of the neurological causes of OCD, and the overlapping with ASD will provide me with the knowledge to consider how may I help my clients, majority whose main neurodevelopmental disorder is ASD. Many of them are high in anxiety, and this could explain the OCD traits in them (Ruzzana, Borsboom, & Geurts, 2014). The disintegration of the brain system has rendered it impossible for them to self-regulate or develop relationships effectively, this could also be contributing to the restricted interests as the mind is inflexible and inclined towards repetitive actions that provide security and stability. There needs to be more enquiry into the negative interaction between ASD and OCD, so that with the increase knowledge and deeper understanding of the underlying environmental, neurobiological and genetic factors that govern the relationship, better diagnostic and treatment options could be made available (Ruzzana, Borsboom, & Geurts, 2014).


American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders:DSM-5. Washington, D.C: American Psychiatric Association.

Ameis, S. H., Lerch, J. P., Taylor, M. J., Lee, W., Viviano, J. D., Pipitone, J.,…Anagnostou, E. (2016). A diffusion tensor imaging study in children with ADHD, Autism Spectrum Disorder, OCD, and matched controls: Distinct and non-distinct white matter disruption and dimensional brain-behavior relationships. The American Journal of Psychiatry, 173(12), 1213-1222. doi:10.1176/appi.ajp.2016.15111435

Anholt, G. E., Cath, D. C., Van Oppen, P., Eikelenboom, M., Smit, J. H., Van Megen, H., & Van Balkom, A. J. (2010). Autism and ADHD symptoms in patients with OCD: Are they associated with specific OC symptom dimensions or OC symptom severity? Journal of Autism and Developmental Disorder, 40(5), 580-589. doi:10.1007/s10803-009-0922-1

Baron-Cohen, S. (2004). The cognitive neuroscience of autism. Journal of Neurology, Neurosurgery and Psychiatry, 75, 948-949. doi:10.1136/jnnp.2004.041293

Davis, D. M., & Hayes, J. A. (2011). What are the benefits of mindfulness? A practice review of psychotherapy-related research. Psychotherapy, 48(2), 198-208. doi:10.1037/a0022062

Di-Cicco-Bloom, E., Lord, C., Zwaigenbaum, L., Courchesne, E., Dager, S. R., Schmitz, C.,…Young, L. J. (2006). The developmental neurobiology of autism spectrum disorder. The Journal of Neuroscience, 26(26), 6897-6906.

Fogel, S. J., & Rosin, M. (2014). Your mind is what your brain does for a living: Learn how to make it work for you. Austin, TX: Greenleaf Book Group Press.

Jacob, S., Landeros-Weisenberger, A., & Leckman, J. F. (2009). Autism specturm and obsessive-compulsive disorders: OC behaviors, phenotypes and genetics. Autism Resource, 2(6), 293-311. doi:10.1002/aur.108

Kreslins, A., Robertson, A. E., & Melville, C. (2015). The effectiveness of psychosocial interventions for anxiety in children and adolescents with autism spectrum disorder: A systematic review and meta-analysis. Adolescent Psychiatry and Mental Health, 9(22), 1-12. doi:10.1186/s13034-015-0054-7

Llosa, P. D. (2011). The neurobiology of “we”. Parabola, , 68-75.

Meier, S. M., Petersen, L., Schendel, D. E., Mattheisen, M., Mortensen, P. B., & Mors, Ole. (2015). Obsessive-compulsive disorder and autism spectrum disorders: Longitudinal and offspring risk. PLoS ONE, 10(11), 1-12. doi:10.1371/journal.pone.0141703

Minshew, N. J., & Williams, D. L. (2007). The new neurobiology of autism: cortex, connectivity, and neuronal organization. Archives of Neurology, 64(7), 945-950. doi:10.1001/archneur.64.7.945

Murray, K., Jassi, A., Mataix-Cols, D., Barrow, F., & Krebs, G. (2015). Outcomes of cognitive behavior therapy for obsessive-compulsive disorder in young people with and without autism spectrum disorders: A case controlled study. Psychiatry Research, 228, 8-13.

Rothschild, B. (n.d.). Emotion in the consulting room is more contagious than we thought [Web log message]. Retrieved from

Ruzzana, L., Borsboom, D., & Geurts, H. M. (2014). Repetitive behaviors in autism and obsessive-compulsive disorder: New perspectives from a network analysis. Journal of Autism and Developmental Disorder, , 1-11. doi:10.1007/s10803-014-2204-9

Schore, A. N. (2014). Early interpersonal neurobiological assessment of attachment and autistic spectrum disorders. Frontiers in Psychology, 5(1049), 1-13. doi: 10.3389/fpsyg.2014.01049

Siegel, D. J., & Solomon, M. (2013). Healing moments in psychotherapy. NY: W.W. Norton & Co.

Siegel, D. J. (2009). Mindful awareness, mindsight, and neural integration. The Humanistic Psychologist, 37, 137-158. doi:10.1080/08873260902892220

Siegel, D. J. (2012). Pocket guide to interpersonal neurobiology. NY: W.W. Norton & Co.

Siegel, D. J. (2012). Developing mind: How relationships and the brain interact to shape who we are (2nd ed.). New York, NY: Guilford Publications.

Siegel, D. J. (2016). Mind: A journey to the heart of being human. New York, NY: W.W. Norton & Company.

Siegel, D. (2006). An interpersonal neurobiology approach to psychotherapy: Awareness, mirror neurons, and neural plasticity in the development of well-being. Psychiatric Annals, , 1-18.

Spiker, M. A. (2012). Restricted interests and anxiety in children with autism. Autism , 16, 306-320.

Stewart, S. E., Yu, D., Scharf, J. M., Neale, B. M., Fagerness, J. A., Mathews, C. A.,…Pittenger, C. (2013). Genome-wide association study of obsessive-compulsive disorder. Molecular Psychiatry, 18(7), 788-798. doi:10.1038/mp.2012.85

Stone, W. S., & Chen, G. (2015). Comorbidity of autism spectrum and obsessive-compulsive disorders. North American Journal of Medicine and Science, 8(3), 109-112. doi:10.7156/najms.2015.0803109

Waska, R. T. (1999). Projective identification, countertransference, and the struggle for understanding over acting out. The Journal of Psychotherapy and Research, 8(2), 155-161.