Why OCD Is Considered Highly Comorbid With ADHD

What Obsessive Compulsive Disorder, ADHD, and Autism have in common

What is O.C.D.?

The DSM-V lists the following criteria for diagnosing O.C.D.:

  1. Recurrent and persistent thoughts, urges, or images that are experienced, at some time during the disturbance, as intrusive, unwanted, and that in most individuals cause marked anxiety or distress.
  2. The individual attempts to ignore or suppress such thoughts, urges, or images, or to neutralize them with some thought or action (i.e., by performing a compulsion).
  3. Repetitive behaviours (e.g., hand washing, ordering checking) or mental acts (e.g., praying, counting, repeating words silently) that the person feels driven to perform in response to an obsession, or according to the rules that must be applied rigidly.
  4. The behaviours or mental acts are aimed at preventing or reducing distress or preventing some dreaded event or situation. However, these behaviours or mental acts either are not connected in a realistic way with what they are designed to neutralize or prevent or are clearly excessive.
  5. The obsessions or compulsions are time-consuming or cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
Created by author

Challenging a common myth about OCD

O.C.D. is not always “I have to wash my hands and check locks constantly”, although these certainly can be compulsions people feel compelled to perform.

O.C.D. is also:

  • Intrusive thoughts
  • Needing things to be a certain way (i.e. symmetry, order, checking)
  • Feeling as though one’s thoughts or actions will cause bad things to happen

OCD is believed to be a common comorbid condition in people with ADHD and is associated with persistent thoughts and urges that cause marked anxiety or distress.

Although more recent research is beginning to challenge these assumptions, I will describe here some of the similarities and differences between ADHD, autism, and OCD, and explain how they overlap.

Executive Dysfunction

It seems we cannot escape it

The most significant commonalities across OCD, ADHD, and Autism are executive functioning deficits.

Many Neurodivergent (ND) folks struggle with cognitive rigidity, which can cause us to become stuck on certain thoughts or events. Many Autistics struggle with black-and-white thinking, perseverance, and difficulty with change.

I personally don’t like how perseverance is described as an attribute when discussing neurotypical (NT) people, yet considered a weakness when discussing ND people, particularly Autistics.

Yes, becoming stuck can be extremely debilitating and distressing at times, but this is not always the case. Hyperfocus and perseverance can lead to incredible productivity and can help us continue working towards a goal in the face of challenges.

This feeling “stuck” can also cause what looks like inattentive behaviour in people with OCD who do not have ADHD.

If your mind is stuck on a past event or a particular thought or worry, it can be difficult to focus on what is happening in the present, causing the appearance of inattention.

However, with ADHD the difficulty is regulating one’s attention. We are easily distracted because our attention can be pulled in many different directions at once, and our brains have difficulty prioritizing which to attend to.

Created by author

Compulsions, impulsivity, and perseveration

Impulsive behaviour refers to actions performed without consideration of the consequences. When we act without thinking through the potential results of our choices, we are being impulsive. If we behave impulsively, we may not even understand why we did what we did.

Compulsive behaviours, on the other hand, are actions one feels compelled to do. These are conscious, intentional acts or behaviours performed in attempts to alleviate fear, anxiety, or stress.

Perseveration is an interesting one. When you look up perseverance, you find the definition “continued effort to do or achieve something despite difficulties, failure, or opposition”.

When you look up the word perseveration on its own, you can find a similar (albeit verbose) definition: “a process that involves lengthy sequences of integrated functions including sustained attention, information processing, and purposeful, planned activity to achieve a goal or solve a problem”.

That’s a pretentious way of saying working hard to achieve something in spite of challenges.

When you look up autistic perseveration, the search returns articles about the problems caused by perseveration, and how to “deal with” or manage perseveration.

Autistic perseveration includes repetitive thoughts, repeating words or phrases (echolalia or verbal stimming), and repetitive motions, movements or behaviours (physical stimming).

Whereas repetitive thoughts and behaviours in those with OCD tend to increase stress and anxiety, Autistic perseveration has been shown to reduce the incidence of depression, and partially mediate symptoms of rejection sensitive dysphoria (RSD).

Opposites attract

Recent research continues to expand upon the similarities and differences in the brains of those with ADHD and those with OCD.

In OCD, it appears over-activity in the cortico-striatal-thalamic-cortical loop (CSTC), which is involved in habit-forming, reward, movement execution, and impulse control.

It is believed this over-activity contributes to obsessive thoughts and repetitive behaviours in those with OCD.

In contrast, ADHD is associated with under-activity in the prefrontal and striatal regions, which lead to difficulty regulating one’s attention, impulsivity, and other executive functioning deficits.

Created by author, based on work by Cabarkapa, et al.

More similarities than differences

It seems as more research is being done on divergent neurotypes such as autism, ADHD, OCD, etc., the more similarities these studies uncover.

In particular, it’s well understood that executive dysfunction plays a significant role in many — if not all — of these neurotypes. The differences lie in how these neurological and developmental changes manifest in each individual.

While it is important to differentiate between these neurologies in order to understand which supports and accommodations may be most helpful, we shouldn’t lose sight of the common traits and characteristics we share.

Most importantly, we should forget the importance and power of our combined voices when we advocate for ourselves and others. The more those of us with lived experience share our knowledge, the better we will be understood and appreciated by the general population.

© Jillian Enright, Neurodiversity MB

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Published by Neurodiversity MB

Jillian has Child and Youth Work diploma as well as a BA in Psychology. Jillian worked on the front lines of Social Services agencies from 2003 - 2012. Jillian has taken numerous continuing education courses and has attended various workshops focused on supporting neurodiverse children, in particular children with ADHD.

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