<p>Different diagnostic systems may assign these syndromes to different categories based on theory or clinical opinion. In the DSM-IV era, OCD was listed under the "Anxiety disorders" category; however, in the DSM-5, it is now listed under a different "Obsessive-Compulsive and related disorders" category. ADHD is currently under the "Neurodevelopmental disorders" category.</p>

<p>However, many would argue that categorization should be based on empirical evaluation of the co-occurrence of syndromes and lower-level symptoms rather than on psychiatric theory or clinical opinion. When approached from this viewpoint, you find that OCD loads highly on the <em>Internalizing</em> spectrum  (along with MDD, GAD, PTSD, and eating disorders) and ADHD loads highly on the <em>Externalizing</em> spectrum (along with substance abuse and conduct-related disorders) and moderately on the <em>Antagonism</em> spectrum (along with narcissism, antisocial, and histrionic disorders). There are many articles on such empirical evaluations and various dimensional and hierarchical approaches to understanding psychopathology that I could share if you are interested. One place to start is would be the <a href="https://medicine.stonybrookmedicine.edu/HITOP/AboutHiTOP" rel="noreferrer">Hierarchical Taxonomy of Psychopathology (HiTOP) system</a>.</p>

CC BY-SA 3.0
2016-06-07T03:04:38.523Z
thank you, jeffrey. why did you list the cluster-B personality disorders except for BPD?
BCLC
CC BY-SA 3.0
2016-06-07T03:11:37.740Z
I didn't include BPD as an exemplar of the antagonism spectrum because it loads on both the internalizing and antagonism spectra. It is a complex and highly heterogeneous diagnosis.
Jeffrey Girard
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2016-06-07T03:19:47.127Z
I like that word heterogeneous. so the other cluster-B are homogeneous?
BCLC
CC BY-SA 3.0
2016-06-07T03:42:13.307Z
No disorder is fully homogeneous, but yes, BPD would appear to be more heterogeneous than other personality disorders. For a very interesting read on this topic, I recommend:
Sharp, C., Wright, A. G. C., Fowler, J. C., Frueh, B. C., Allen, J. G., Oldham, J., & Clark, L. A. (2015). The structure of personality pathology: Both general (’g') and specific ('s') factors? Journal of Abnormal Psychology, 124(2), 387–398.
Jeffrey Girard
CC BY-SA 3.0
2016-06-07T04:24:04.477Z
Jeffrey, this one? http://www.ncbi.nlm.nih.gov/pubmed/25730515
BCLC
CC BY-SA 3.0
2016-05-19T13:39:23.547Z
2016-05-19T13:39:23.547Z
Jeffrey Girard
<p>ADHD is considered a <a href="https://en.wikipedia.org/wiki/Neurodevelopmental_disorder" rel="noreferrer">neurodevelopmental disorder</a>.</p>

<blockquote>
  <p>Neurodevelopmental disorders are impairments of the growth and development of the brain or central nervous system. A narrower use of the term refers to a disorder of brain function that affects emotion, learning ability, self-control and memory and that unfolds as the individual grows.</p>
</blockquote>

<p>You are correct in that OCD is generally considered an anxiety disorder. They are not the same because ADHD is characterized by cognitive impairment, and OCD is characterized by anxiety (in the form of obsessions and compulsions). However, you can find both disorders in one person.</p>

CC BY-SA 3.0
2015-09-07T07:48:17.683Z
Thanks Sydney Maples! Is OCD neurodevelopmental as well? '[Obsessive compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD) are two of the most common neuropsychiatric diseases in paediatric populations](http://cogsci.stackexchange.com/questions/11102/are-adhd-and-ocd-under-some-type-of-mental-illness#comment22030_11102)'?
BCLC
CC BY-SA 3.0
2015-09-07T17:52:39.643Z
@JackBauer There was nothing in that paper that suggested that OCD is a neurodevelopmental disorder, from what I can tell. I think it mentioned that because ADHD was neurodevelopmental, its symptoms typically showed up before OCD symptoms do. OCD is characterized by anxiety, which may or may not affect cognitive impairment, and ADHD is characterized by cognitive impairment, which may or may not produce anxiety.
Sydney Maples
CC BY-SA 3.0
2015-09-07T23:42:29.543Z
Sydney Maples, it says neuropsychiatric. Not neurodevelopmental, but has 'neuro' in it. And apparently there is a neurobiological link between OCD and ADHD. Just to be clear, OCD isn't neurodevelopmental?
BCLC
CC BY-SA 3.0
2015-09-07T23:44:43.167Z
Is there any kind of category under which OCD and ADHD are? Neuro something? Also, sorry for linking error. I edited link for spectrum in the post
BCLC
CC BY-SA 3.0
2015-09-07T23:48:59.797Z
@JackBauer It has 'neuro' in it to refer to the nervous system, of which neuropsychiatric disorders are all a part ('psychiatry' involves the study of these disorders). Within neuropsychiatric disorders there are many different types of disorders. 'Neurodevelopmental' disorders are disorders that impair development within the nervous system. A 'neurobiological' link means that they may share similar properties within the biology of the brain, similar to how there may be a link between the biology of memory and the biology of imagination. But it doesn't mean they are in the same camp.
Sydney Maples
CC BY-SA 3.0
2015-09-07T23:51:36.893Z
@JackBauer OCD is not considered a neurodevelopmental disorder because it is not characterized by its effect on development of the brain or nervous system. It is characterized by anxiety that produces obsessive thoughts about what the anxiety focuses on, as well as compulsions to do certain things to get rid of the anxiety. For that reason, it is an anxiety disorder, not a neurodevelopmental disorder. 'Anxiety disorder' is the category it is under. ADHD is under the 'neurodevelopmental disorder' category. It is characterized by impaired development in the brain, typically in the frontal lobes.
Sydney Maples
CC BY-SA 3.0
2015-09-14T13:52:59.327Z
to your knowledge, is there a category of mental illnesses that includes ADHD and OCD? Apparently, there's an impulsive-compulsive spectrum. The word 'spectrum' brings to mind [bipolar](http://autism.wikia.com/wiki/Bipolar_disorder), wherein both mania and depression are mood disorders...right?
BCLC
CC BY-SA 3.0
2015-09-14T13:53:51.437Z
From the [article](https://iocdf.org/expert-opinions/expert-opinion-ocd-and-adhd-dual-diagnosis-misdiagnosis-and-the-cognitive-cost-of-obsessions/): Some research has suggested that OCD and Obsessive Compulsive Spectrum Disorders fall upon a compulsive-impulsive continuum. In other words there exists a gradient of disorders ranging from behavioral impulsivity to compulsivity. OCD appears to lie at one end of this spectrum, while ADHD exists at the other.
BCLC
CC BY-SA 3.0
2015-09-15T01:53:25.347Z
@JackBauer that isn't true, because that is implying that you cannot have both at once, though it is often the case that OCD and ADHD occur together. I do think that that article is mistaking OCD with OCPD, which as far as I know is essentially the opposite of ADHD.
Sydney Maples
CC BY-SA 3.0
2015-09-15T14:41:21.800Z
What exactly is 'that', and how does that imply one cannot have both OCD and ADHD? One can have both mania and depression (which is what bipolar disorder is)
BCLC
CC BY-SA 3.0
2015-09-04T03:44:32.423Z
2015-09-04T03:44:32.423Z
Sydney Maples
<p>Related to <a href="https://cogsci.stackexchange.com/questions/11101/can-adhd-and-ocd-coexist-is-it-in-the-same-way-mania-and-depression-can-coexist">question</a>.</p>

<p>Mania, hypomania, depression and bipolar are <a href="http://triadmentalhealth.org/the-five-5-major-categories-of-mental-illness/" rel="nofollow noreferrer">mood disorders</a>, <a href="http://vignette2.wikia.nocookie.net/autism/images/d/da/Mania-Depression_Scale.gif/revision/latest?cb=20070625164835" rel="nofollow noreferrer">from what</a> I <a href="http://autism.wikia.com/wiki/Bipolar_disorder" rel="nofollow noreferrer">understand</a>.</p>

<p>Are ADHD and OCD under some category as well? From what I understand, the are opposite ends of some <a href="https://iocdf.org/expert-opinions/expert-opinion-ocd-and-adhd-dual-diagnosis-misdiagnosis-and-the-cognitive-cost-of-obsessions/" rel="nofollow noreferrer">impulsive-compulsive spectrum</a>?</p>

<p>OCD is an <a href="http://triadmentalhealth.org/the-five-5-major-categories-of-mental-illness/" rel="nofollow noreferrer">anxiety disorder</a> (same link as earlier), from what I understand, but what about ADHD? Is there another description of OCD that also applies to ADHD?</p>

CC BY-SA 3.0
2015-09-04T02:26:34.720Z
You might like to read this: The neurobiological link between OCD and ADHD http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4148591/
Yvonne Liew
CC BY-SA 3.0
2015-09-07T08:09:00.317Z
Thanks @YvonneLiew. So they're both neurodevelopmental?
BCLC
<depression><adhd><mood><anxiety><bipolar-disorder>
Are ADHD and OCD under some type of mental illness?
BCLC
# Are ADHD and OCD under some type of mental illness?

(Asked by: username_0 on 2015-09-04)

Related to [question](https://cogsci.stackexchange.com/questions/11101/can-adhd-and-ocd-coexist-is-it-in-the-same-way-mania-and-depression-can-coexist).

Mania, hypomania, depression and bipolar are [mood disorders](http://triadmentalhealth.org/the-five-5-major-categories-of-mental-illness/), [from what](http://vignette2.wikia.nocookie.net/autism/images/d/da/Mania-Depression_Scale.gif/revision/latest?cb=20070625164835) I [understand](http://autism.wikia.com/wiki/Bipolar_disorder).

Are ADHD and OCD under some category as well? From what I understand, the are opposite ends of some [impulsive-compulsive spectrum](https://iocdf.org/expert-opinions/expert-opinion-ocd-and-adhd-dual-diagnosis-misdiagnosis-and-the-cognitive-cost-of-obsessions/)?

OCD is an [anxiety disorder](http://triadmentalhealth.org/the-five-5-major-categories-of-mental-illness/) (same link as earlier), from what I understand, but what about ADHD? Is there another description of OCD that also applies to ADHD?

**Tags:** depression, adhd, mood, anxiety, bipolar-disorder

> **Comments:**
> **username_1**: You might like to read this: The neurobiological link between OCD and ADHD http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4148591/  
> **username_0**: Thanks @YvonneLiew. So they're both neurodevelopmental?  

---

## 2 answers

### Answer by username_2 on 2016-05-19. Score: 5

Different diagnostic systems may assign these syndromes to different categories based on theory or clinical opinion. In the DSM-IV era, OCD was listed under the "Anxiety disorders" category; however, in the DSM-5, it is now listed under a different "Obsessive-Compulsive and related disorders" category. ADHD is currently under the "Neurodevelopmental disorders" category.

However, many would argue that categorization should be based on empirical evaluation of the co-occurrence of syndromes and lower-level symptoms rather than on psychiatric theory or clinical opinion. When approached from this viewpoint, you find that OCD loads highly on the *Internalizing* spectrum (along with MDD, GAD, PTSD, and eating disorders) and ADHD loads highly on the *Externalizing* spectrum (along with substance abuse and conduct-related disorders) and moderately on the *Antagonism* spectrum (along with narcissism, antisocial, and histrionic disorders). There are many articles on such empirical evaluations and various dimensional and hierarchical approaches to understanding psychopathology that I could share if you are interested. One place to start is would be the [Hierarchical Taxonomy of Psychopathology (HiTOP) system](https://medicine.stonybrookmedicine.edu/HITOP/AboutHiTOP).

> **Comments:**
> **username_0**: thank you, jeffrey. why did you list the cluster-B personality disorders except for BPD?  
> **username_2**: I didn't include BPD as an exemplar of the antagonism spectrum because it loads on both the internalizing and antagonism spectra. It is a complex and highly heterogeneous diagnosis.  
> **username_0**: I like that word heterogeneous. so the other cluster-B are homogeneous?  
> **username_2**: No disorder is fully homogeneous, but yes, BPD would appear to be more heterogeneous than other personality disorders. For a very interesting read on this topic, I recommend: Sharp, C., Wright, A. G. C., Fowler, J. C., Frueh, B. C., Allen, J. G., Oldham, J., & Clark, L. A. (2015). The structure of personality pathology: Both general (’g') and specific ('s') factors? Journal of Abnormal Psychology, 124(2), 387–398.  
> **username_0**: Jeffrey, this one? http://www.ncbi.nlm.nih.gov/pubmed/25730515  

---

### Answer by username_3 on 2015-09-04. Score: 5

ADHD is considered a [neurodevelopmental disorder](https://en.wikipedia.org/wiki/Neurodevelopmental_disorder).

> Neurodevelopmental disorders are impairments of the growth and development of the brain or central nervous system. A narrower use of the term refers to a disorder of brain function that affects emotion, learning ability, self-control and memory and that unfolds as the individual grows.

You are correct in that OCD is generally considered an anxiety disorder. They are not the same because ADHD is characterized by cognitive impairment, and OCD is characterized by anxiety (in the form of obsessions and compulsions). However, you can find both disorders in one person.

> **Comments:**
> **username_0**: Thanks username_3! Is OCD neurodevelopmental as well? '[Obsessive compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD) are two of the most common neuropsychiatric diseases in paediatric populations](http://cogsci.stackexchange.com/questions/11102/are-adhd-and-ocd-under-some-type-of-mental-illness#comment22030_11102)'?  
> **username_3**: @JackBauer There was nothing in that paper that suggested that OCD is a neurodevelopmental disorder, from what I can tell. I think it mentioned that because ADHD was neurodevelopmental, its symptoms typically showed up before OCD symptoms do. OCD is characterized by anxiety, which may or may not affect cognitive impairment, and ADHD is characterized by cognitive impairment, which may or may not produce anxiety.  
> **username_0**: username_3, it says neuropsychiatric. Not neurodevelopmental, but has 'neuro' in it. And apparently there is a neurobiological link between OCD and ADHD. Just to be clear, OCD isn't neurodevelopmental?  
> **username_0**: Is there any kind of category under which OCD and ADHD are? Neuro something? Also, sorry for linking error. I edited link for spectrum in the post  
> **username_3**: @JackBauer It has 'neuro' in it to refer to the nervous system, of which neuropsychiatric disorders are all a part ('psychiatry' involves the study of these disorders). Within neuropsychiatric disorders there are many different types of disorders. 'Neurodevelopmental' disorders are disorders that impair development within the nervous system. A 'neurobiological' link means that they may share similar properties within the biology of the brain, similar to how there may be a link between the biology of memory and the biology of imagination. But it doesn't mean they are in the same camp.  
> **username_3**: @JackBauer OCD is not considered a neurodevelopmental disorder because it is not characterized by its effect on development of the brain or nervous system. It is characterized by anxiety that produces obsessive thoughts about what the anxiety focuses on, as well as compulsions to do certain things to get rid of the anxiety. For that reason, it is an anxiety disorder, not a neurodevelopmental disorder. 'Anxiety disorder' is the category it is under. ADHD is under the 'neurodevelopmental disorder' category. It is characterized by impaired development in the brain, typically in the frontal lobes.  
> **username_0**: to your knowledge, is there a category of mental illnesses that includes ADHD and OCD? Apparently, there's an impulsive-compulsive spectrum. The word 'spectrum' brings to mind [bipolar](http://autism.wikia.com/wiki/Bipolar_disorder), wherein both mania and depression are mood disorders...right?  
> **username_0**: From the [article](https://iocdf.org/expert-opinions/expert-opinion-ocd-and-adhd-dual-diagnosis-misdiagnosis-and-the-cognitive-cost-of-obsessions/): Some research has suggested that OCD and Obsessive Compulsive Spectrum Disorders fall upon a compulsive-impulsive continuum. In other words there exists a gradient of disorders ranging from behavioral impulsivity to compulsivity. OCD appears to lie at one end of this spectrum, while ADHD exists at the other.  
> **username_3**: @JackBauer that isn't true, because that is implying that you cannot have both at once, though it is often the case that OCD and ADHD occur together. I do think that that article is mistaking OCD with OCPD, which as far as I know is essentially the opposite of ADHD.  
> **username_0**: What exactly is 'that', and how does that imply one cannot have both OCD and ADHD? One can have both mania and depression (which is what bipolar disorder is)  

---

