Saturday, May 30, 2009

Modafinil: An alternative treatment for ADHD and comorbid substance abuse?

Can Modafinil (Provigil) Replace Stimulant Medications in Adult ADHD where stimulant drug abuse is a concern?

It is a Catch-22 of the ADHD world. An individual is suffering from severe ADHD symptoms and appropriate stimulant medications may help remedy some of the negative side effects of the disorder. However, due to the high prevalence of substance abuse in ADHD (some officials put the rate of comorbid substance abuse as high as to 30% in the ADHD population), including stimulant medications such as amphetamines, treatment of ADHD symptoms via stimulant medications cannot, by nature of the comorbid substance abuse disorder, be a treatment option.

The appearance of (relatively) novel non-stimulant medication alternatives such as Strattera (atomoxetine), have offered individuals with ADHD another treatment alternative. However, the results are often mixed. Strattera often works well with the inattentive-dominated forms of the disorder, but the positive results are often not as pronounced for the more hyperactive or impulsive forms of ADHD, especially if comorbid disorders such as conduct-related issues surface.

Another alternative may be a completely different type of drug, which, while not a stimulant in its own right, can act on or exhibit pseudo-stimulant properties. It appears that in at least some cases, Modafinil (Provigil) may be the type of drug we're looking for in these cases.

**Blogger's note: The extent of the study highlighting this case for Modafinil treatment for ADHD and comorbid amphetamine abuse is intended for adult treatment only. Given the relative scarcity of research on medication options for adult ADHD symptoms (compared to those designed more for children), this post is designed for offering a possible treatment alternative for ADHD in adults. Nevertheless, some recent studies have shown promising results of Modafinil as an ADHD treatment method for children and adolescents.

It is important to note, that while not initially designed as an ADHD-specific medication (and not a stimulant in its own right), Modafinil does share at least some degree of overlap with several stimulant agents for ADHD treatment. One is its regulation of catecholamines (important neuro-signaling chemical agents, whose balance in and out of neuronal cells is crucially important for regulating attention, hyperactive and impulsive behaviors, and locomotor control). As far as its mode of action and metabolism (clinical pharmacokinetics of Modafinil) are concerned, drug-drug interactions between Modafinil and several ADHD stimulant medications such as methylphenidate or dexamphetamine (Dexedrine) appear to be limited.

A background note on addiction potentials of ADHD drugs: This section is an aside, and is meant to serve as some background information and to clear up potential confusion surrounding ADHD medications and their addiction potentials. The next four paragraphs may be skipped if you are pressed for time.

While I cannot stress enough the importance of regulating neuro-chemical balance for both the onset of ADHD as well as drug addiction (which are affected by pharmacological agents such as ADHD medications, in varying forms), it is the rate of action for which these chemical changes take place which typically drives a particular drug's addiction potential.

Unfortunately, this last fact is often lost in much of the literature surrounding ADHD treatment (especially those which promote non-pharmaceutical treatments for the disorder). For example, many "natural" ADHD treatment books and websites frequently start out by asserting (erroneously) that methylphenidate is the equivalent of crack cocaine, and promotes later drug abuse and addiction.

While this blogger is a personal advocate for natural approaches to treating ADHD whenever possible (and without compromising overall treatment effectiveness in ADHD treatment), he wants to make it clear that significant differences do exist between ADHD medications and stimulant street drugs. One of the most telling signs of this is the rate of uptake and clearance of drug-like agents into and out of the brain, respectively. In general, the quicker a substance is taken up into the central nervous system and the faster it clears the brain, the more likely this chemical agent will elicit a "high" and an increased tendency towards substance dependence.

ADHD medications like Ritalin, while having some degree of overlap in structure and net effects of action as cocaine, are specifically designed to have a much slower rate of release and clearance, significantly reducing their abuse potential compared to cocaine. We have previously discussed Ritalin (methylphenidate) vs. cocaine addiction potentials in earlier posts.


Modafinil: Modes of action and addiction potential:


The reason I am providing all of this information is the fact that the successful regulation and softening of rapid spikes and clearances of chemical peaks is a crucial component to curbing the drug addiction process. It is believed that modafinil may work so well at reducing drug cravings by targeting this very mechanism. Unlike many stimulant medications which can produce some type of "high" (especially if abused by snorting or injection, or taken at abnormally high doses), Modafinil has a low abuse potential, and offers several other advantages over methylphenidate.

Modafinil does have a relatively positive track record for mitigating substance abuse disorders. For example, the administration of Modafinil can attenuate cocaine dependence. In contrast, methylphenidate (Ritalin, Concerta, Metadate, Daytrana), while being very effective as an ADHD treatment, does little to curb comorbid substance abuse disorders in ADHD patients. Unfortunately, the effectiveness of Modafinil on treating comorbid substance abuse disorders in individuals with ADHD may be limited to specific drugs. For example similar positive effects of Modafinil on nicotine dependence appear to be less pronounced.

Modafinil may also offer advantages over traditional stimulants as well. As a cognitive enhancement type of pharmacological agent, modafinil may be useful in improving the work performance of adults with ADHD by improving short-term memory and visual recall, impulse control, and spatial skills (all of which are frequent deficits in children and adults with ADHD). Additionally, similar improvements were seen in individuals with schizophrenia, suggesting the diversity of modafinil's range of performance in cognitive improvement. These improvements are typically not seen in individuals unaffected by psychological disorders, further supporting the evidence that modafinil is less likely to be abused recreationally in the general population.

The potential implications of modafinil for ADHD treatment may be further reaching than the details outlined in the original article (and basis of this post, highlighting the effects of modafinil on amphetamine abuse in adult ADHD). For example, modafinil, as a vigilance-promoting medication, can offset an afternoon dip in arousal state (which has implications on many of the shorter-acting stimulant medications, which begin to wear off around this time). This may be useful for individuals with sleep disorders (which are common in ADHD), as well as regulating circadian rhythms. In a post earlier this month, we investigated the relationship between ADHD and seasonal affective disorders, and hinted at the association between ADHD and disruption in circadian rhythms.


Potential future implications of Modafinil as an ADHD treatment alternative:


Additionally, while Modafinil may offer benefits for the whole ADHD spectrum, this blogger hypothesizes that it may be most useful for treating the inattentive subtype of the disorder. Some reasons for this are as follows:
  • Activity patterns and circadian rhythms may often be associated with ADHD subtype. For example, "morning people" with ADHD may have a tendency to fall into the more hyperactive/impulsive group, while "eveningness" is more of an inattentive ADHD trait, suggesting more of a disruption in the circadian rhythms of inattentive ADHD'ers.
  • Additionally, non-stimulants often have somewhat of a better track record with the inattentive subtype of ADHD compared to the more hyperactive/impulsive subtypes. The uses of the non-stimulant atomoxetine (Strattera), highlight this general trend. While atomoxetine treatments often result in drastic improvements in all ADHD subtypes, negative side effects are often less seen in the inattentive subtype.
  • Compared to stimulants, non-stimulant medications for ADHD often do a better job at not exacerbating comorbid disorders such as obsessive compulsive or anxiety disorders (which are often more common to the ADHD inattentive subtype). Additionally, Modafinil treatment can be useful in treating adults with ADHD and a history of mood disorders.
  • Modafinil offers advantages over methylphenidate as far as fewer side effects including appetite suppression, sleep disturbances and heart rate dysfunction (orthostatic tachycardia, which essentially is significant changes in heart rhythms based on postural changes, such as standing up quickly from a seated position).
  • Anecdotal evidence, as noted by the Modafinil and amphetamine abuse study mentioned earlier, also suggests that Modafinil may be a useful treatment method for "refractory" cases, or individuals who have consistently shown poor response to other treatment medications and interventionary measures.
  • Finally, it is important to note (and this was also touched on in the Modafinil and amphetamine abuse study), that Modafinil treatment may be better suited for the more "controlled" abusers of stimulants. In other words, better effects might be seen for adults who regularly take illegal stimulant drugs such as amphetamines as a conscious effort to "self-medicate" for their ADHD, as opposed to an out-of-control drug addict who craves the drugs on a non-scheduled basis.
Given the high propensity of comorbid disorders when deciding on treatment for ADHD, as well as practicality issues concerning the administration of medicinal agents for treatment of the disorder in adults, I see a fair amount of potential for Modafinil's "off-label" usage as a treatment alternative to stimulants in adults with ADHD.

Friday, May 29, 2009

Does Blood Type Affect ADHD?

This blog has often discussed the wide range of genetic influences on ADHD and related disorders. Some of the ADHD genes we have previously investigated include:

Additionally, some of these genes may work together in combo. For example, a combination of specific variations in the DAT1 gene and the DRD4 gene may associate with IQ and behavioral disorders as they relate to ADHD.

The main point of all of these examples was not to overwhelm anyone, but rather to highlight the intricate relationship between genetics and ADHD heritability.

Adding to this extensive list may be a new set of genes related to blood types and ADHD.

**For a quick synopsis of blood types, please consult the italicized paragraphs below. Otherwise you may skip to the next paragraph highlighting a new study on blood type and ADHD.

Human blood types are often classified by the "ABO" system. "A" and "B" refer to immune-regulating factors and play a major role in blood transfusions. These blood types are acquired from our parents and can come in dominant and recessive forms. Genes for blood type can be found on the 9th human chromosome.

They are the two main (or dominant) forms of immune-regulating blood factors. Additionally, A and B can be "codominant", that is an individual can have a mixture of the two. For these "codominant" individuals, their blood type is labeled "AB". If an individual has neither "A" nor "B", he or she is labeled as an "O".

In essence, if you have a specific letter(s), you can donate blood to individuals who share your same letters (there are actually other important factors and donor restrictions besides this, such as the "Rh factor", but for sake of simplicity, we will just discuss "ABO" for the moment). For example, a person with type "A" blood could donate to another person who has "A" or "AB" because both "A" and "AB" would recognize the "A" component. They could not donate to a "B" or an "O" blood type because these individuals' bodies would not be able to recognize the "A", resulting in a severe immuno-rejection problem.

An "O" could donate to and "A", a "B", an "AB", or another "O" (again, there are detailed exceptions to this generalization), because "O" does not have either of the "A" or "B" markers on it, so the recipient's body would not see anything "foreign" about this. This makes "O" carriers better candidates for blood donation. On the flip side, and individual with type "AB" could take blood from and "A", a "B", an "AB" or an "O" since their blood already recognizes the "markers". This makes AB candidates better recipients for blood.

In addition to an individual's blood type governing the blood transfusion process, blood types may also confer resistance or susceptibility to certain bodily dysfunctions or diseases. For example, type "A" individuals may be naturally more prone to cancers of the digestive system, and individuals with type "O" are more prone to cholera, plagues, or even malaria (interestingly, they may be more prone to be preferred targets of mosquitoes, compared to the other blood types).

Overview of an original study on ADHD and blood types:
Returning to our main discussion, it appears that certain blood types may also be related to an increased likelihood of childhood ADHD or related disorders. A Chinese study recently came out which sought to investigate whether certain blood types were actually more likely to be affiliated with ADHD. The results, while preliminary, should nevertheless pique some interest on the topic among professionals.

Here are some of the major highlights of the study:
  • Blood types (using the "ABO" format) were taken from 96 children and their parents, to determine the heritability patterns of blood types.
  • Both ADHD and non-ADHD children were observed in the study, and their blood types were broken down.
  • The study found that children who did have ADHD were more likely to have inherited either the "A" or "O" type blood from their parents.
  • Conversely, children who inherited the type "B" blood (which would include either the "B" or "AB" form) were less likely to be diagnosed with ADHD.

** A caveat concerning the findings and reproducibility of this study: It is important to note that the study population was relatively small, especially for a study of this magnitude which seeks to identify general trends between blood types and their relative association with co-existing disorders. Some blood types can be relatively rare, for example, in the United States, only around 10% of the population has type "B" blood and only about 15% has the "B" in any form (types B or AB). Although blood types vary extensively all over the world, certain types tend to predominate, which requires large populations to be studies to ensure all groups are sufficiently represented. Thus, small population studies can easily produce skewed results. Nevertheless, I personally believe this study was a good starting point.

**Blogger's personal notes/opinions on these findings:

I found this study to be interesting. Unfortunately, I could not read the whole article (the majority is in Chinese!), but the possibility of blood typing being related to ADHD would be a major breakthrough, if these results are able to be consistently replicated with larger population studies.

My first thought was that maybe some nearby gene related to ADHD might be influencing the blood type/ADHD connection, but no significant genes associated with ADHD exist on the 9th chromosome (at least to the best of my knowledge after conducting a search of OMIM for the term "ADHD", a national database which ties down diseases and disorders to known genetic regions). However, genes which are located far apart from each other, even on completely different chromosomes can also work in tandem, so genetic relationships between ADHD genes and blood type genes cannot be ruled out entirely.

Another option may be some type of indirect connection between blood type and ADHD. For example, the article notes that individuals who have the "O" or "A" blood type alleles are more prone to ADHD. Other sources note that individuals with type "O" are more prone to developing intestinal and gastric ulcers, and that individuals with type "A" are more prone to cancers of the digestive system (such as cancers of the esophagus, pancreas and stomach). This may signify that these blood types (compared to those who have "B" or "AB" blood) may be more prone to digestive problems.

Digestive disorders can result in poor nutrient absorption (we have discussed nutrient deficiencies in ADHD in number of previous posts), which may leave one more prone to ADHD symptoms. Additionally, digestive dysfunctions can actually lead to an increased likelihood of developing food allergies, as potential allergens are less likely to be broken down or "chewed up" than by a properly-functioning digestive system. Furthermore, we have also explored the possibility that acid accumulation can make its way into the brain regions and have an impact on neurological symptoms including ADHD-like behaviors. This was discussed in a recent post investigating the high prevalence of ADHD in children who suffer from frequent ear infections.

While these possibilities are strictly hypothetical at the moment I firmly believe that we should further explore the possibility of specific blood types as possible underlying causes or risk factors for developing ADHD.

Wednesday, May 27, 2009

ADHD and Balance Impairment: Visual and Inner Ear Deficiencies

Balance dysfunctions and visual or vestibular deficiencies: Uncommon comorbids in the ADHD spectrum:

When we think of comorbid disorders to ADHD, we often envision disorders which can be diagnosed psychiatrically. Common examples such as depression, anxiety, Obsessive Compulsive Disorders (OCD), oppositional defiant disorders, and conduct disorders often come to mind. In addition, it is perhaps no surprise that learning disabilities are relatively common in children and adults with ADHD. If we do delve into physical comorbid disorders, things like Tourette's and tics may come to mind. For those skilled in the diagnosis and treatment of ADHD, even non-trivial comorbids such as bedwetting and sleep disorders may be apparent.

However, there is another impairment that often goes along with the ADHD population, especially in children. Sensory processing disorders are often seen in the ADHD population, especially in children. This includes more "physical" dysfunctions including the ability of the child to maintain balance and equilibrium. To the frustrated parent of coach of an ADHD child, this may introduce another complication with regards to sports or other activities which involve coordination and balance, such as basketball, baseball, tennis, soccer, gymnastics, musical instruments, dance, etc.

The aim of this post is to investigate and discuss impairments in balance function in children with the disorder, We will be citing and highlighting some key studies in the overlap between ADHD and balance dysfunctions (especially relating to functions derived from visual and tactile signals) and look for possible underlying causes and treatment methods:

Brain regions involved in Balance Dysfunction in the ADHD Child:
Most experts often cite specific "hot spot" regions of the brain for the ADHD patients. Among these, the prefrontal cortex part of the brain often receives the most attention. Less pronounced, however, are the studies associating the cerebellum, and their implications on ADHD. For a reference to the Prefrontal Cortex and Cerebellum brain regions, please consult the brain diagrams below:
Shown above is a human brain. The Cerebellum region, which plays a major role in governing balancing functions and may be compromised in a significant subsection of ADHD children, is shown in purple in the top picture. The area highlighted in orange in the bottom drawing roughly corresponds to the prefrontal cortex region of the brain, which plays a major role in impulse control. Deficiencies in blood flow and overall activity of this prefrontal cortex region of the brain are often seen in children (and adults) with ADHD, and may be responsible for some of the difficulties in filtering out comments and actions for appropriateness.


The inter-relationship between attention and balance/coordination: The strong association of the prefrontal cortex and cerebellum regions of the brain:


Many studies involving brain regions and ADHD often miss this connection. The relationship between these brain regions may go a long ways in explaining ADHD comorbid disorders as well, especially the more "physical" ones such as speech complications, developmental coordination disorders, etc. While perennial "hot spot" brain regions, such as the prefrontal cortex, are frequently mentioned in studies involving brain activity in ADHD, this particular brain region is actually intricately interconnected with the cerebellum (as well as another key brain region, the basal ganglia. The role of the basal ganglia in kids with ADHD has been discussed previously in other postings, but in general, the basal ganglia tell how fast a person "idles". 'Type A' personalities, such as workaholics, individuals with OCD and overly focused individuals typically have overactive basal ganglia, whereas many with ADHD often exhibit underactive basal ganglia.).

We have already mentioned that the balance-governing regions of the brain (the cerebellum) is interconnected with a key impulse-control region of the brain (the prefrontal cortex or PFC). We also mentioned that impulsivity is a characteristic of the Hyperactive-impulsive and Combined ADHD subtypes (as opposed to the more inattentive forms of the disorder). Interestingly, the prevalence of balance dysfunction cases seems to predominate in the combined subtype of ADHD (main paper as reference source). This correlation lends further credence to the hypothesis that the balance-governing and impulse-governing regions of the brain may be "co-affected" in the case of the balance-deficient, hyper-impulsive ADHD child.

Key points concerning balance related deficiencies and ADHD:
  • ADHD is often associated with developmental delays. Indeed, studies highlighting a delay in cortical maturation in children with ADHD suggests that children and teens with the disorder may fall "behind the curve". By its own very nature, the vestibular system often does not fully develop until the age of 15, so immature development in this brain region may result in deficiencies in this system throughout almost the entire span of childhood in an individual with ADHD.

  • Additionally, EEG and imaging studies have also demonstrated relative deficiencies in both size and activity (by measuring blood flow patterns) in various brain regions of ADHD children. These include the cerebellum and the caudate nucleus. Both are interconnected and associate with the "ADHD region" of the prefrontal cortex (PFC). This PFC region plays a major role in the impulse-control process and deficiencies in its function can result in a weak self-regulatory system of impulsive behaviors (which are hallmark characteristics of ADHD, especially in the hyperactive/impulsive and Combined subtypes).

  • The cerebellum gathers input from visual, vestibular (inner ear), and somatosensory (mainly tactile senses, such as perceived through the skin and internal organs) systems. As we can imagine, a defect in one or more of these information-obtaining sensory systems, and the cerebellum (as well as the interconnected region of the PFC) may be compromised. Thus ADHD and sensory deficits may be intricately related.

  • Taking this one step further, we may wish to explore the link between ADHD and sensory disorders, including processing disorders and sensory integration disorders. One thing is for sure, however: ADHD is not simply limited to deficits in the PFC!

  • The vestibular system also plays a crucial role in what is known as "gaze stabilization" (i.e., stabilizing the focus on a particular fixed object when you yourself are moving). The very nature of "gazing" obviously has visual implications as well, so a deficiency in the vestibular component of gaze stabilization may also affect visual input success as well. Interestingly (an perhaps not surprisingly), visual input deficiencies are also seen at high rates in children with ADHD.

    This may actually serve as one of the key contributing factors as to why maintaining attention (to, say, a teacher), may be so difficult for ADHD kids, because they literally are having trouble focusing their visual attention (gaze) on their target of interest (i.e. a teacher standing up in class giving a lecture), especially if the child is already fidgeting around in their seat. In other words, there may be some inherent deficiency in this particular component of the attention span, and needs to be addressed further in the near future.
Investigating the sources of balance impairment in children with ADHD:
In order to clarify where I am coming from on this, I will highlight an extremely recent publication in the Journal of Pediatrics by Shum and Pang. This study investigated the different systems of balance in children, including somatosensory (balance governed by tactile features), visual, and vestibular (inner ear and the sense of equilibrium). They tested approximately 50 children (ages 6-12) with ADHD for balance discrepancies by isolating each of the three systems listed above to test sensory organizations of balance. A highlight of the study can be seen below:

Instruments/Methods of the study:
  1. A platform which can induce a feeling of motion on a child who stands upon it (this disrupts the somatosensory component of balance, forcing the child to use their visual or vestibular functions to compensate for the somatosensory impairment).
  2. Surrounding scenery which can visually give the illusion of motion. This forces the child to use their vestibular and somatosensory methods of equilibrium, as the visual sense is disrupted. Another variation of this is to have the child perform with their eyes closed.
  3. A combination of the two methods above will isolate the vestibular component of balance, as both the somatosensory and visual sources of balance are now both compromised.
  4. A total of six different environmental conditions were performed to isolate one or more senses of balance. The researchers noted which of the three modes of balance were most likely to be compromised in the ADHD children. The findings are highlighted below:
While balance-related issues can stem from visual discrepancies, somatosensory issues (i.e. the sensations of touch and pressure from the skin and even internal organs), and vestibular (inner ear) imbalances, it appears that ADHD children are most likely to suffer from visual imbalances. This is closely followed, however, by deficits in vestibular function. Somatosensory difficulties appear to occur in ADHD children as well, but the role of this system is likely to be much smaller than for the other 2.

Possible academic implications of balance dysfunction and ADHD: Does the source of an ADHD child's balance deficiency affect his or her sensory learning style? The following points are simply the result of this blogger thinking out loud. Nevertheless, these might be some good topics of future study, as balance difficulties may be useful in evaluating academic strategies.
  • These findings on balance may even extend to the classroom and affect the learning environment of an ADHD child. Given the above, abnormalities in these areas may even affect a child's mode of learning and learning style. While these assertions simply remain personal hypotheses of this blogger, a child with visual discrepancies leading to balancing difficulties may also be deficient in visual perception and therefore struggle in a visual-dominated learning environment. He or she may gravitate towards a more auditory or kinesthetic style of learning.
  • Conversely, it is also possible that vestibular-regulated balance dysfunctions, which stem from the inner ear may actually extend to a child's auditory learning capabilities. Again, this remains a hypothesis, but given the fact that severe childhood ear infections can affect both balance and hearing (as well as ADHD symptoms, see previous post on childhood ear infections and ADHD), a child with vestibular-related balance deficiencies may also have more difficulty in a predominantly auditory-based learning environment. This may spell bad news if an ADHD child's teacher engages in more auditory discussions or as the child moves up to high school and college courses where an auditory lecture is the more common form of teaching and communication.
  • A double-whammy?: Given the fact that children with ADHD may suffer from both vestibular and visual (and even somatosensory) information processing for balance, it leads us to wonder if the child may also have learning deficits in 2 of the 3 major forms of learning (visual, auditory or kinesthetic). If this is the case, trying to accommodate an ADHD child's education could be extremely difficult, if he or she must heavily rely on only one predominant mode of acquiring and processing information.

    For example, if a child were to undergo a study similar to the one listed above, and it turns out that he or she is weak in both the visual and vestibular forms of balance, and (this is a big "if" and is only hypothetical at the moment) the whole balance governing/learning style hypothesis holds true, he or she may have to rely on a predominantly kinesthetic form of learning. While this child may succeed in hands-on learning subjects (i.e. frog dissection or wood shop class), he or she may have an exceedingly difficult time in other subjects such as algebra or history where hands-on-learning opportunities are more difficult to implement.

  • The role of balance and sensory stimulation may have even greater-reaching academic implications. Another study just came out recently investigating the role of posture stability (i.e. how well a person stabilizes their center of balance) on ADHD and dyslexia. The study found that comorbid ADHD symptoms greatly influenced the effects of posture stability in dyslexic individuals, which may even have implications to affecting the reading environment of the individuals with dyslexia. It's important to keep in mind that this study involved adults instead of children, but the fact that ADHD may play such an integrated role into sensory modulation of other disorders into adulthood may signify the deep level of inter-relationship between cognitive function and sensory motor stimulation.
Vestibular Stimulation as an alternative form of ADHD Treatment?: As an interesting aside, there has been some pronounced effect on treating ADHD symptoms with a non-pharmaceutical alternative method called vestibular stimulation. We will be addressing the validity of these findings and their potential for practical usage in a later discussion.

Friday, May 22, 2009

Childhood Ear Infections and ADHD: Why the link?

When we scan the literature for statistics on ADHD and search for early warning signs or tip-offs that a young child may be prone to the disorder, a few common trends seem to pop up again and again. One of these is the high rates of ADHD and attentional difficulties in kids suffering infection of the middle ear (Otitis Media) in early childhood.

During early childhood, the actual positioning of the ear canal is still adjusting, the pathway into the middle part of the ear is actually at a flatter angle than in a mature adult. This difference in positioning actually makes younger children much more prone to ear infections than older children or adults. Unfortunately, these infections may increase the risk of further complications down the road, including an increased onset of attentional difficulties, including ADHD. Here is what some of the literature has to say about the ADHD/ear infection connections:

Relationship between middle ear infections and inattention: The basis for inattentive ADHD?

The main culprit for attentional deficits is often believed to be the result of hearing loss (even mild), early in a child's life due to complications with the middle ear, including infections, allergy-related causes or build-up of fluids in the canal. As a result, the child begins to miss out on verbal cues, and does not develop the same level of response to an adult voice. Auditory deficiencies (including auditory processing disorders) may stem from this key development period, even if the hearing difficulties are only temporary.

Not surprisingly, there is a wealth of data associated with hearing loss due to middle ear complications can lead to language processing difficulties. We have seen how auditory processing disorders can often occur as a comorbid factor in ADHD, and may be linked to seemingly unrelated behaviors including comorbid anxiety and conduct-related disorders.

It is important to note, however, that other early childhood studies have not seen a link between infection and attentional difficulties (observed by parents, teachers, or clinicians).

Interestingly, environment may play a huge role in explaining this discrepancy between study results. One study found that children who had middle ear complications early on along with poor home environments were significantly more likely to develop attentional difficulties (along the lines of what would be classified as ADHD). Therefore, the effects of early ear infections on compromised attentional difficulties may be significantly reduced if a supportive home environment is maintained for a child. This is good news for parents of children with ear infections. But what about the hyperactive component of ADHD?

The link between hyperactive behaviors and middle ear complications: The basis for hyperactive/impulsive or combined subtype ADHD?

While it seems more intuitive that ear infections could lead to auditory problems and subsequent attentional difficulties (especially to auditory cues), the relationship between ear infections and hyperactivity is less inherently obvious. This association would be more relevant to the hyperactive/impulsive and combined subtypes of ADHD.

For over 30 years, researchers have linked high rates of ear infections and hyperactivity (this study used the term "minimal brain dysfunction", a phrase which this blogger has personal objections, nevertheless, it is a relatively common term in the literature). Later studies confirmed these findings, including one which reported the majority of children medicated for hyperactivity had a past history of 10 or more childhood ear infections. These numbers were in sharp contrast to the prevalence of ADHD in non-hyperactive children.

One thought may be that ADHD which includes a significant hyperactive component (as opposed to the more inattention-dominated form of the disorder) is more likely to be associated with comorbid disorders that correspond to ear infections. We have seen previously that comorbid disorders to ADHD are often related to particular subtypes.

For example, anxiety and depressive-like symptoms are often more likely to co-exist with primarily inattentive ADHD, while conduct disorders are more likely to co-exist if there is a high hyperactive/impulsive behavior (especially in the combined subtype). In general, the prevalence of more severe learning disabilities is often more associated with the inattention-dominant form of ADHD, while motor tics are more likely to be a hyperactive/impulsive trait. Carrying these associations in mind, are the studies linking early ear infections to hyperactivity simply due to associations with hyperactive subtype-dominated comorbid disorders?

One particular study found that children with hyperactivity vs. children with learning disabilities (and not hyperactivity, remember, learning disabilities are often seen at higher rates in the inattentive forms of the disorder) had similar numbers of total childhood ear infections. However, the timing of the infections did seem to matter. Children with hyperactivity experienced more recent ear infections (within the previous year) compared to the learning disability kids.

In other words, the question surrounding hyperactivity and ear infections may be more of a "when" question than a "how many" question. This may also suggest the possibility that hyperactivity due to middle ear troubles may be more of a temporary condition (this is supported by trends as an individual with ADHD ages, typically, the hyperactive symptoms of the disorder begin to subside as a child gets older and reaches adulthood, while the inattentive symptoms are more likely to plateau) as opposed to inattentive problems stemming from ear infections. Severity of the infections may also be a triggering cause or associated warning sign of an increased risk of developing hyperactive behaviors. The same study found that earaches and upper respiratory tract infections were higher in the hyperactive group than in the less-hyper learning disability group.

So what's going on with the connection between ear infections and ADHD-like hyperactivity?:
Although none of the above studies mentioned this possibility, as a blogger I have a few ideas on the subject. One of the most probable reasons for the ear infection/hyperactivity correlation may be due to the treatment process of ear infections. Let me explain:

Ear infections are typically treated with antibiotics. While these drugs work wonders for most infections, they also can disrupt the healthy bacterial counts in the digestive tract (that is, they kill off many of the "good" bacteria in our digestive systems in addition to the "bad" bacteria which may be causing our infections).

If the "good" digestive bacterial counts fall too low, the digestive process is compromised. The absorption and digestion process may suffer, as key nutrients may now be compromised (even if no major dietary changes occur). We have spoken extensively about nutrient deficiencies and ADHD as well as ADHD-related nutrition strategies in earlier posts.

Additionally, if good bacterial counts fall low, incomplete digestion results, which can lead to byproducts such as higher concentrations of organic acids, as well as incomplete breakdowns of potential allergens (which can increase sensitivity to food allergens, among others). These allergens and acids can actually begin to penetrate the blood brain barrier and show up in higher concentrations in the brain. Neurological disorders, including abnormal hyperactivity may actually be triggered by digestive imbalances (to a degree beyond what most of us realize). We are just beginning to recognize the huge degree of inter-relationship between the nervous and digestive systems, including brain-gut interactions.

There has been a longstanding "hot" discussion surrounding food allergies and ADHD (as well as possible connections between food allergies and disorders like fibromyalgia and chronic fatigue syndrome), and the disrupted bacterial balance in the digestive system due to frequent antibiotic usage for recurrent ear infections may be a governing factor. This seems to make sense, especially considering the fact that hyperactivity was more linked to recent ear infections (and resultant antibiotic treatment), while the more inattentive behaviors and learning disorders seem to be a more long-standing symptom. Since bacterial counts begin to re-stabilize following antibiotic treatment (if a proper diet is maintained), the food-related hyperactivity may begin to subside, but for recent infections and treatments, the digestive bacteria may still be imbalanced, triggering an onset of ADHD-like hyperactive behaviors.

Of course this is just the blogger's personal hypothesis, but it at least seems plausible that the actual treatment for ear infections may play an equally strong role on the high rate of occurrence between ADHD and ear infections.

Sunday, May 17, 2009

Ginkgo biloba for ADHD: A natural herbal treatment alternative?

A few weeks ago, I discussed the merits of ginseng for treating ADHD. What I did not mention is the fact that this special herb often works even better in tandem with another important "brain herb", Ginkgo biloba. It's benefits also extend beyond the nervous system, and the Ginkgo has been used to treat everything from increasing blood flow to Alzheimer's to glaucoma to hormone replacement to protection against neuronal degradation. While somewhat wary (personally) of using generalized "brain booster" nutrients for ADHD (it is a highly variable disorder of complex etiology and treatment methods), I am interested whenever new research publications arise on the topic. Just this week, a new paper came out on the merits of Ginkgo biloba as an ADHD treatment option.

Here are some of the major points of the publication:

  • Irritability is an often overlooked side effect of ADHD. Medications, especially over-prescription with stimulants such as methylphenidate and amphetamines can increase this unwanted side effect. However, Ginkgo exhibited a positive mollifying effect on irritability for the individuals in the study.

  • While one of the knocks against Ginkgo biloba is that it can sometimes result in sedative effects, the study found these to be extremely mild. However, to go along with the irritability-reducing benefits above, Ginkgo was able to improve the individuals' tolerance for frustration (to the degree that this behavior could be measured).

  • We have seen previously that oppositional defiant behaviors are often comorbid to ADHD (which can often manifest themselves alongside seemingly unrelated disorders such as auditory processing disorders or even bedwetting). One of the strongest suits of Ginkgo biloba may actually be in curbing these oppositional behaviors. This suggests that Ginkgo may be effective for the more Hyperactive/Impulsive or Combined Subtypes of ADHD, where comorbid oppositional behaviors are more often seen (as opposed to the predominantly inattentive subtype of the Disorder).

  • Nevertheless, Ginkgo biloba appeared to boost symptoms of attention and working memory as well. This may suggest Ginkgo's versatility, and that it could be used universally across the ADHD "spectrum", including for the 3 classic or traditional subtypes of the disorder.

  • The study highlights the relative success for co-treatment with methylphenidate and clonidine for individuals with ADHD and comorbid anxiety disorders. The authors suggest a functional comparison between Ginkgo and clonidine, and hint at its use as an alternative to clonidine/methylphenidate treatment (of course, it is also possible that Ginkgo may be used alongside lower doses of stimulant medications, which could be very useful in reducing unwanted side effects, which are often mild for low doses of stimulants, but typically begin to appear with greater frequency when stimulant dosing is increased). Thus, Ginkgo could possibly act as a side-effect-saving alternative to higher doses of medication.

  • As a precautionary measure, due, in part to some of its anti-clotting properties, there is some concern about Ginkgo triggering internal cerebral bleeding. Indeed, other studies have also addressed this possible concern, highlighting issues such as haemmorrhage risks, as well as herb-drug interactions with Ginkgo and anti-coagulant medications.

  • Keep in mind the extremely small nature of the study (only 6 individuals) should be met with healthy skepticism. However, the results were still notable. Statistically significant reductions in some of the trademark ADHD symptoms (fidgeting, restlessness, inattention, etc.) upon Ginkgo biloba treatment definitely highlight its potential as a more "natural" alternative treatment method for ADHD.