Sunday, March 1, 2009

ADHD and Auditory Processing Disorders

ADHD and Auditory Processing Disorders can share a number of overlapping symptoms and behaviors in children. However, when these two disorders exist alongside each other as comorbid disorders, then the two can feed off of each other and increase the likelihood of onset of a third (or fourth) psychological or developmental disorder. A recent publication done by Ghanizadeh on ADHD and auditory processing problems found that two other disorders commonly associated with or comorbid to ADHD were more likely to appear if an auditory processing problem exists in an ADHD child. I am not going to cover the contents of the whole article, but some of the main points are listed below:

  • Auditory processing disorders are independent from the mechanical process of hearing (in other words, the peripheral hearing, or ability to pick up background sounds is not affected), but rather have difficulties in the screening, filtering and differentiating "important" sounds from background noise. Difficulties in this result in an impaired ability to utilize important auditory information properly. On an interesting side note, it appears that methylphenidate (Ritalin, Concerta, Daytrana), which is a common stimulant medication for ADHD, may actually help improve auditory processing in children. Perhaps, on an equally interesting note, the dietary mineral zinc has also been associated with information processing disorders in boys with ADHD. In an earlier blog post, we covered the topic of how supplementation with zinc could boost Ritalin's effectiveness. Therefore, it is possible that a similar underlying cause and mechanism may be at work behind ADHD and auditory processing disorders and their effective treatments, at least in this blogger's opinion.

  • Auditory processing problems were divided into two subcategories in the article, hyposensitivity (under-reacting or under-processing a sound/auditory stimulus) and hypersensitivity (over-reacting or over-processing a sound/auditory stimulus) to sound (an actual distinction whose existence was questioned by the author towards the end of the article). Both types can lead to similar behaviors or deficits, including difficulties screening important sounds from background noise, picking out verbal cues and selectively listening to an important voice (i.e. a parent's or teacher's voice amongst the chatter of other children), and (not surprisingly) an increased tendency towards distraction. Perhaps not surprisingly, deficits in language comprehension, utilization and verbal skills, as well as learning problems often do not fall far behind when an auditory processing disorder is present.

  • Although hypo- and hyper-sensitivity may be two sides of the same coin, it is interesting to note that they each appear to be correlated to different comorbid disorders common to ADHD. For example, ADHD children with comorbid auditory hypersensitivity are (at least based on data from the study) more likely to exhibit characteristics of a separation anxiety disorder (which is characterized by apparent stress or emotional outbursts when separated from a parent or particular loved one). What is interesting about this is the fact that separation anxiety behaviors typically decrease with age, but, according to the Ghanizadeh article, hypersensitivity shows little age-related correlation.

  • On the other hand, auditory hyposensitivity which occurs alongside ADHD is more likely to be associated with Oppositional Defiant Disorder (ODD), which is characterized by long-term verbal hostility, arguing, intentional disobedience, and disrespectful behaviors towards authorities. ODD can be an early symptom of later conduct disorders, which include violent and criminal behaviors. In addition, an accompanying oppositional defiant disorder can increase ADHD symptoms.

  • Additionally, these findings are interesting because they buck some of the trends and associations previously seen in comorbid disorders. For example, hypersensitivity in other sensory areas such as touch is frequently seen in Separation Anxiety and related disorders. This "touch" hypersensitivity is more frequently seen in girls. However, with regards to the ADHD/auditory processing/separation anxiety disorder component of the study, gender differences were not observed. This may suggest either that the gender effects on sensory hypersensitivity and its connection to separation anxiety disorders may reside more in the tactile form of sense, while auditory hypersensitivity has a much smaller gender component with regards to anxiety disorders. As a quick aside, we have looked at another form of sensory hypersensitivity recently in a post titled Does ADHD Improve your Sense of Smell?

In conclusion, we should take home two important messages from this article:

  1. Children diagnosed with ADHD may often be missed for a comorbid diagnosis of auditory processing difficulties, a fact which is seen by the high degree of overlap between ADHD and auditory processing disorders and their shared symptoms.

  2. Additional comorbid disorders such as anxiety disorders or defiant behaviors may actually provide clues that an underlying sensory processing disorder (such as an auditory processing difficulty) is present. Of course there are numerous potential causes to any of these accompanying disorders, but if a prescribing physician is borderline on diagnosing an ADHD child with an additional auditory processing disorder, the presence or absence of a comorbid separation anxiety disorder or persistence of oppositional behavior may prove to be a potentially useful tool for pointing the physician in the right direction if the Ghanizadeh study findings are verified and replicated by additional works.

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10 comments:

Anonymous said...

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Debra Sale Wendler - Respect Effect Mom said...

Hello. I believe you got the cart and the horse confused here.

Children with severe ADHD are often thought to have auditory processing problems BECAUSE they have 6-second attention spans, as do all children with ADHD. This can be expanded with treatment.

Further, children with the hyperactive impulsive and combined subtypes of ADHD develop ODD, not the other way around.

Sincerely yours in parenting success,
Debra Sale Wendler

The ADHD Treatment Guide said...

Thanks for the comments.

When a comorbid disorder exists alongside ADHD, it is not uncommon for the ADHD to show up 2-3 years before the other disorder (such as oppositional behavior disorders or even auditory processing disorders). So it is correct that oppositional defiant disorders often appear later than ADHD. A possible exception to this is when early onset oppositional or conduct behaviors appear at a young age, often more concurrent with ADHD. Generally the earlier the onset of these other disorders, the closer the tie-in to ADHD (especially with conduct disorders).

It is also true that for auditory processing disorders, treatment with the common ADHD stimulant methylphenidate has been shown to be useful in multiple cases.

However, based on the general trends of evidence that I've seen, auditory processing disorders are independent of ADHD subtype, while other disorders such as oppositional defiance disorders are more tied in with the hyperactive/impulsive or combined ADHD subtypes (as Debra correctly mentioned).

This, combined with the number of cases in which an auditory processing disorder is present aside from ADHD symptoms, suggest that there is a fair degree of distinction between the two disorders. However, as Debra mentioned, the overlap of symptoms between the two can be very similar, so much that ADHD-based attentional difficulties may mask a separate underlying comorbid auditory processing disorder.

Nevertheless, a large number of ADHD children I work with actually show a tremendous preference for auditory learning, and do not exhibit any type of delayed processing difficulties. In addition, I work with several children with auditory processing difficulties, who exhibit no other major symptoms of ADHD, so there is a fair amount of evidence supporting a significant distinction between the two.

Thanks for the great comments and positive remarks.

Anonymous said...

I just found this blog while searching for info regarding comorbidity of ADHD and CAPD. We have long suspected (as have her psychologist and OT) that my ADHD daughter also has CAPD, but have been told that she's been too young to test her for that.

What is interesting to me is that her CAPD symptoms seem much more apparent when she is unmedicated. She takes Strattera and it does not start working for the first hour she's awake. During that hour, she doesn't hear anything I say, and it's not defiance (all the time). She'll ask me to repeat over and over, even for simple commands I would think she could infer from the situation. Are you aware of any research related to that?

Anonymous said...

Believe it or not there are a number of highly trained professionals who think the whole concept of ADHD and many other labels used in this WEBSITE are all BOGUS

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suraj said...

There are a number of different types of treatments for anxiety disorders. Your GP may prescribe you one of the following medicines, depending on how much your anxiety affects you.

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Shonda said...

Oh my god, there is really much helpful info here!

Anonymous said...

My nephew with Behavioral Variant Frontotemporal Dementia got that "oppositional defiant" dx first. ADHD is too broad, and too many serious illnesses are misdiagnosed because they share the same symptoms.