Around 85% of the UK’s population are ‘neurotypical’ and the other 15% are known as ‘neurodivergent’. But what does this mean? Neurotypical defines individuals with behavioural traits and brain function that are regarded as ‘normal’ in society, whereas neurodivergent refers to individuals who exhibit behavioural traits and brain function that are not considered to be normal within society. Neurodiverse conditions include ADHD, ASD, Dyslexia, Dyspraxia, Developmental Language Disorder, Foetal Alcohol Spectrum Disorder, Tourette’s and Tic Disorders, and more! [1] They tend to be co-morbid with many conditions, including addictions and anxiety disorders such as OCD.

What is OCD?

OCD stands for ‘Obsessive-compulsive Disorder’ and is a disorder related to anxiety. OCD is characterised by two main components: obsessional thoughts and compulsive behaviours. You can read more about OCD on our blog here.

This week is OCD awareness week, 9th – 15th October, and, in this article, we want to look at the relationship between OCD and other neurodiverse conditions such as ADHD and ASD.

You may be thinking that these are all very different conditions – and you are correct! However, there are many overlapping symptoms and behaviours which can make neurodiversities hard to recognise and differentiate between them.


Firstly, let’s look at OCD and Autism Spectrum Disorder (ASD) .

Autism is a neurodevelopmental condition characterised by deficits in three main areas: social communication, social imagination and social interaction, with sensory sensitivities also being present. Read more about Autism on our website here.

There are many overlapping symptoms, or behaviours, between these two conditions.

  • Compulsive-like behaviours
  • Restricted and repetitive behaviours
  • Fixation on routines
  • Ritualised patterns of behaviour
  • Resistance to change
  • Restricted interests

It is the social imagination part of autism that may present as comparable to the symptoms of OCD, with repetitive and restricted behaviours, adherence to routines, and obsessive special interests being defining characteristics.

Restricted and repetitive behaviours are clearly a significant similarity and are part of the diagnostic criteria in the DSM-5 for both conditions. These behaviours include repetitive actions  that are exhibited in an inappropriate manner in relation to the situation and context. [2]

Anxiety has a part to play regarding restricted and repetitive behaviours in both conditions, so how are the two conditions different?

Both those with OCD and autistic people will get anxious when these behaviours are intercepted, however, the main difference between OCD and ASD in relation to the above behaviours is the result. [3] Are they causing happiness and comfort, through stimming and special interests, or are they a necessity to curb anxiety and an impending sense of doom? Are the behaviours themselves causing the individual distress? Although this is a very generalised difference, and extremely hard to determine, autistic people often display these behaviours because they are gaining sensory pleasure (or discomfort) from the world around them.

The role of anxiety in relation to the cause of restricted and repetitive behaviours is substantially different in ASD and OCD. Obsessive behaviours in OCD can trigger anxiety as the actions and thoughts are often not conducive to the individual’s identity and can be distressing. Whereas, in autistic individuals, it is apparent that routine and restricted interests have a calming effect on anxiety – despite some researchers suggesting these behaviours may contribute to social ostracisation  [2].  In contrast, many autistic people feel that their special interests have enabled them to connect with others and learn valuable social and communication skills.


If there are so many similarities between OCD and Autism, you may think ‘Attention Deficit Hyperactivity Disorder’ (ADHD) and OCD are completely opposite disorders, with one characterised as attention deficit and the other a fixation on small details. However, there may be more crossovers than you think.

ADHD is a group of behavioural symptoms that include inattentiveness, hyperactivity and impulsiveness. You can find out more about ADHD on our website here.

Co-morbid neurodiverse conditions are common in individuals with ADHD, with 30-50% of those with ADHD also having other conditions including OCD, anger, learning disabilities, tic disorder and difficulty regulating emotion including anxiety and mood disorders. [4]

Both OCD and ADHD are related to neurotransmitter brain chemistry in the frontal lobe, however, OCD is associated with serotonin and research into dopamine functioning has been central to most ADHD research.

Again, as with ASD and OCD, it is important to determine the origin of the behaviour. Is the behaviour caused by executive dysfunction? Or is the behaviour the result of obsessive, compulsive thoughts that cannot be resisted? Are the behaviours impulsive or compulsive?

Those with ADHD often develop coping mechanisms to avoid being overwhelmed due to inattention, forgetfulness and untidiness, and these skills may look like behaviours typical of OCD. These behaviours are however the result of the individual being able to cope with their neurodivergence in a way that is beneficial to their mental health, in contrast to OCD where these behaviours are not the result of coping skills but are compulsions that may themselves be causing distress.

See your GP

All three of the conditions discussed above have in-depth diagnostic criteria, and this blog post only looks at a small section of overlapping symptoms to compare how the conditions can be difficult to recognise.

Overall, it is important to remember that OCD, ASD and ADHD are all very different conditions. ASD and ADHD are neurodevelopmental conditions – meaning they are present both in childhood and adulthood – whereas OCD is a mental health condition that can present at any point in life. All of these conditions affect an individual’s life in unique ways – no one requiring more or less support than the other.

If you are diagnosed with any of these neurodiverse conditions and you think there may be other conditions present, or if you haven’t been diagnosed, but see yourself in some of the behaviours above, make sure you arrange a chat with your GP.