ADHD and Handwriting: What's the Connection?

The link between ADHD and Poor Handwriting (Dysgraphia):

It has been well-known for years that individuals with ADHD are often more prone to problems with penmanship, that is, they have trouble producing legible handwriting. But why is this the case? There are several theories out there, and multiple studies showing how effective ADHD treatments can also result in major improvements with a person's handwriting. I will review some of the current findings on the topic:

1. A group in Israel sought to investigate whether the problem with handwriting in ADHD children was due more to underlying language problems (i.e. spelling, formulating sentences, etc.) or more due to the mechanical problem of the physical writing process. While they concluded both were at play, the results of their study seemed to indicate that underlying language difficulties played only a secondary role to the writing difficulties and that the primary cause was due to "non-linguistic deficits". Interestingly, the group did find specific patterns to the frequent mis-spellings of words, instead of a host of random, unrelated errors. This blogger personally found the conclusion of the article's summary to be particularly amusing, as it recommended a "judicious use of psychostimulants".
   
   
2. Continuing on with the "judicious use of psychostimulants" theme, we must investigate the effectiveness of one of the most common types of stimulants for ADHD, methylphenidate (Ritalin, Concerta, Metadate). This drug has elicited a number of positive effects as far as improving both the cognitive and physical aspects of handwriting, as concentration or attentional lapses subside, allowing the thought process and physical act of writing to be performed simultaneously.
   
   However, another study found that even medication with methylphenidate had its limits, and that handwriting gradually deteriorated as the child continued with the writing process. This suggests that for long essays or standardized tests (such as the writing portion of the SAT's, or A.P. exams), medication with methylphenidate or other stimulants may only be useful early on.
   
   
3. Specific Genetic Factors may underlie both ADHD and handwriting problems: There was an interesting study done by a Dutch group which suggests that there may be some sort of genetic factor that inhibits fine motor movements (such as those required for writing) which then make their way over to ADHD. In other words, this study seems to suggest that ADHD is a secondary problem to fine motor problems such as dysgraphia (typically, it's the other way around, where ADHD is considered the primary disorder). This study discovered that non-ADHD siblings (who, by definition, share half of the ADHD child's genes, provided they are not identical twins) of the ADHD children also had difficulties with more complex forms of the writing process, compared to the general population. In other words, these siblings had some degree of impairments with the writing process, but not to the degree of their ADHD siblings.
   
   This suggests that these non-ADHD siblings may have enough genetic "impairments" to share some of the comorbid writing problems as their ADHD counterparts but not enough to manifest an outright diagnosis of ADHD themselves. In other words, the comorbidity (co-occurrence of) ADHD and dysgraphia is apparently not an all-or-nothing phenomena.
   
   
4. Differences in hand-eye coordination and motor control problems are more pronounced in the left hand for ADHD vs. non-ADHD children: We have previously investigated key brain regions commonly associated with ADHD, including differences in relative brain region size, use of brain regions, bloodflow patterns, brain electrical activity patterns, sense of smell, the relationship to alcoholism, brainwave patterns, and genetic differences targeting specific brain areas.
   
   However, it is worth noting that these brain regional differences are often not laterally symmetric, that is they may only be on the left side or right half of a particular brain region. This lopsidedness may play a role in manual dexterity and motor coordination differences between ADHD and non-ADHD individuals, which appear to be even greater in the left hand (which, in most cases the non-dominant one).
   
   The article which found this discrepancy between the different sides of the body goes on to suggest that testing for fine motor coordination in ADHD kids would be better suited for the left hand, since the effects are more pronounced. This leads to this potentially intriguing question: If handwriting is done with the dominant hand, does it stands to reason that handwriting difficulties are just the tip of the iceberg with regards to immensely greater fine motor difficulties? In other words, if an ADHD child is having trouble writing with his or her dominant right hand, how bad would the fine motor deficits be if they needed to use their left hand for something like catching a baseball, or shooting a left-handed layup in basketball?
   
   Based on this finding, it appears that poor handwriting may be just one aspect of a much larger fine motor disability. Another possibility, however, is that using one's non-dominant hand requires a higher order cognitive process than utilizing one's dominant hand for a routine task. This possibility may actually carry some weight, as we have seen in previous posts how discrepancies between ADHD and non-ADHD individuals begin to balloon as the cognitive processes become increasingly more difficult.
   
   This also seems to jive with the underlying genetic component of these disorders proposed by the ADHD sibling study in the previous point, in which the non-ADHD siblings had trouble only with the higher-order writing processes and not the more automatic ones (such as doing a simple task with one's dominant right hand). Unlike the Israeli study, this seems to favor more of an underlying cognitive discrepancy as the main culprit of poor handwriting in ADHD, as opposed to a more "mechanical" one.
   
   
5. The genetic discrepancies in ADHD and fine motor impairments may be one of motor timing: Going back to the genetic aspects of ADHD and motor impairments such as dysgraphia for a moment, it is worth mentioning another finding by a group investigating difficulties in timing fine motor applications in ADHD children. This study utilized tests such as pressing a button on self-determined one second intervals (and measuring how close the child's perceived timing matched up with "real" one-second intervals), tapping one's finger as many times as possible within a given time limit (a relatively common test for individuals with ADHD and related disorders) and tests which measured reaction timing to moving objects and visible changes (which may have direct implications as to how well a child would perform in a sport involving reacting to moving objects, such as baseball, lacrosse, or tennis). Based on these tests, the authors concluded that the motor impairments in the ADHD children were more likely due to timing issues as opposed to generalized motor problems.
   
   As a blogger's note, this might explain some of the difficulties in the handwriting mechanics, such as crossing "t's" and dotting "i's", which essentially involves hitting a "target" on the paper, or keeping up with a teacher while taking notes (which is a very time-dependent process which often requires a fast execution of handwriting numbers, letters, diagrams, and symbols).

A number of books on the subject of ADHD and writing disorders show actual handwriting samples of children on and off medication for ADHD. The differences are astounding. Additionally, differences in complexity and eloquence in creating stories are often extremely pronounced depending on the mode of expression. For example, actual cases involving gifted children with ADHD have highlighted how a child can concoct an thorough, detailed, and well-rounded story orally, but when asked to write out the same story, he or she is scarcely able to construct even a single, legible, coherent paragraph.

This brings up the important issue as to whether children with ADHD should be afforded opportunities to use different modes of communication for their assignments, such as dictating or typing as opposed to handwriting. It appears that for many, the actual process demanded of ADHD children for actually writing may rob or ferret away the majority of their cognitive capacity, resulting in a barren landscape of creativity or eloquence.

Given the fact that many children with ADHD respond positively to alternative learning or expressive styles such as predominantly auditory (dictating) or kinesthetic (typing) means of expression, numerous questions surrounding the degree of accommodation for these ADHD children must be addressed. It is my personal hope that the findings of some of these studies will shed some light onto the mechanical and cognitive impairments of the physical writing process for children with ADHD will help shape an educational environment to help these children to flourish.

Does ADHD improve your sense of smell?

Due to a high degree of overlap in symptoms with other disorders, finding accurate ways of differentiating ADHD is of utmost importance. Based on a recent study by Romanos and coworkers, it appears that individuals with ADHD may be able to "sniff out" their disorder. In a publication on Improved Odor Sensitivity in ADHD, Romanos and others found that children with ADHD had significantly better sensitivity for particular odors when compared to their non-ADHD peers. In other words, children with ADHD may be able to better detect minute or trace levels of certain smells when compared to other children. As an interesting aside, the study noted that boys actually had a slight advantage as far as odor detection when compared to girls (which goes against many other study findings which indicate that females have better senses of smell).

However, when these children were investigated in two other "smell" categories, which included discrimination between different smells, and the actual identification of particular agents causing the smell, they should no advantages over their non-ADHD peers. Similar studies have also been done on adults with ADHD, and have shown little to no effect between ADHD and sense of smell. These findings seem to agree with another recent report on olfactory impairments in children with ADHD. This study found that children with ADHD were worse at identifying the nature of particular odors than non-ADHD children. It appears that these deficits are tied to a specific brain region called the orbitofrontal region, the outer section which is approximated by the green region in the diagram below (original file source can be found here). Note that this region has numerous implications with regards to the disorder of ADHD.

To throw another wrinkle into the mix, it appears that stimulant medication treatments for ADHD may negate these olfactory advantages (with regards to the increased ability of ADHD children to detect minute levels of odors better than their peers). The Romanos study also investigated another group of similar age and gendered individuals with ADHD who were on the medication methylphenidate (Ritalin, Concerta, Daytrana, etc.). Like the non-medicated ADHD children, this group all had the combined subtype of ADHD (meaning that both hyperactive/impulsive as well as inattentive symptoms were present to a large extent). They found that the medicated children did not have the improved smell sensitivity that their non-medicated ADHD peers did, but rather had an odor detectability level similar to that of the non-ADHD group. In other words, it appeared that methylphenidate (as well as other ADHD stimulant medications, potentially), may offset any improvements in smell detection in ADHD individuals.

It is believed that the dopamine system and pathways play a critical role in smell differences between ADHD children and their peers. Keep in mind that methylphenidate and most other stimulants for ADHD work by increasing the concentration of the neurotransmitter dopamine in the areas between neuronal cells, by reducing the transport of this important brain chemical into the cells themselves (individuals with ADHD often have an imbalance between the dopamine levels inside and outside of these neurons, and often have insufficient dopamine levels in the surrounding areas outside the neuron cells). Dopamine levels have been shown to have a protective effect on olfactory neurons (neurons related to smell). Chemical alterations of dopamine levels, such as those introduced by methylphenidate or other ADHD stimulants may therefore interfere with odor sensitivities in key regions of smell such as the olfactory bulb region of the brain.

On a final note, the findings by Romanos and coworkers are of potential interest because of the fact that many neuropsychiatric disorders are accompanied by a sharp decrease in odor detection and sense of smell. These include Parkinson's Disease, obsessive-compulsive disorder (OCD), schizophrenia, autism, and depression. Because of this, it may be possible to use odor sensitivity tests to help differentiate between ADHD and other neuropsychiatric disorders, at least in children. Although we have seen that there is some conflicting evidence surrounding studies, it appears that we could, at least in theory, administer some type of smell test of trace levels of specific odorous chemical agents that are undetectable to the majority of the child population and see whether the potential ADHD candidate could detect these minute traces. Furthermore, it would be interesting to see whether other stimulant medications besides methylphenidate have the same effects on curbing the increased odor sensitivities exhibited in ADHD children.