View Full Version : ADHD characteristics in Canadian Aboriginal children.


mildadhd
04-07-14, 02:15 AM
ADHD characteristics in Canadian Aboriginal children.


Abstract


OBJECTIVE:

The authors examine how many Aboriginal children attending two reservation-based elementary schools in Northern Alberta, Canada, would demonstrate symptoms

associated with ADHD using standardized parent and teacher questionnaires.


METHOD:

Seventy-five Aboriginal children in Grades 1 through 4 are tested. Seventeen of the 75 (22.7%) Aboriginal children demonstrated a match on parent and teacher

forms, with T-scores greater than 1.5 standard deviations from the mean on the Conners' ADHD Index, Diagnostic and Statistical Manual of Mental Disorders (4th

ed.; DSM-IV) Hyperactive/Impulsive Index, DSM-IV Inattentive Index, and/or DSM-IV Total Combined T-score.


RESULTS:

The number of Aboriginal children found to have symptoms associated with ADHD is significantly higher than expected based on prevalence rates in the general

population.


CONCLUSION:

These findings suggest either a high prevalence of ADHD in Aboriginal children or unique learning and behavioral patterns in Aboriginal children that may erroneously

lead to a diagnosis of ADHD if screening questionnaires are used.


http://www.ncbi.nlm.nih.gov/pubmed/16648231




http://www.youtube.com/watch?v=-ryC74bbrEE

Corina86
04-07-14, 07:03 AM
22.7% match the criteria for ADHD?! This is a huge number. I hope they will do more research on this subject. I would be interested what percentage of adults have ADHD, especially the parents of the children with those symptoms. Plus things like diet and lifestyle. Not to mention genes and brain scans.

Lunacie
04-07-14, 09:39 AM
22.7% match the criteria for ADHD?! This is a huge number. I hope they will do more research on this subject. I would be interested what percentage of adults have ADHD, especially the parents of the children with those symptoms. Plus things like diet and lifestyle. Not to mention genes and brain scans.

Yes, that is one small study. It will be interesting to see if further research replicates those results.

mildadhd
04-07-14, 10:47 AM
22.7% match the criteria for ADHD?! This is a huge number. I hope they will do more research on this subject. I would be interested what percentage of adults have ADHD, especially the parents of the children with those symptoms. Plus things like diet and lifestyle. Not to mention genes and brain scans.



The first thing, that needs to be addressed, is the real affects of emotional distress.

(I am sure all humans, have the same basic emotion genetic script)




Peripheral

Lunacie
04-07-14, 11:15 AM
The first thing, that needs to be addressed, is the real affects of emotional distress.

(I am sure all humans, have the same basic emotion genetic script)




Peripheral

I think the other things Corina mentioned (heredity, lifestyle, diet, brain scans) also need to be addressed.

There surely isn't any need to only look at one thing at a time when there are many people doing research?

We simply don't know at this time which thing(s) will be the key.

mildadhd
04-07-14, 01:09 PM
I think the other things Corina mentioned (heredity, lifestyle, diet, brain scans) also need to be addressed.

There surely isn't any need to only look at one thing at a time when there are many people doing research?

We simply don't know at this time which thing(s) will be the key.



I think emotional distress is a primary factor.

How do you rule out the obvious emotional distress?


Peripheral

namazu
04-07-14, 01:37 PM
I think emotional distress is a primary factor.

How do you rule out the obvious emotional distress?
To see if emotional distress is a primary factor,
you could compare First Nations children from this community,
with and without ADHD symptoms,
to see whether those with ADHD
were more likely to have experienced emotional distress at an early age
(or have parents/caregivers who experienced emotional distress)
than those without ADHD.

Or, you could follow kids from birth
(or mother becoming pregnant)
until age 12 or so and document stressors
and presence or absence or degree of ADHD symptoms.

In both cases, you'd also need to consider
whether or not the parents had displayed symptoms of ADHD as well,
consider genetic heritability,
and tease out whether associated issues (like smoking or drug use or parental impulsivity)
might also affect the children's ADHD symptoms
in ways that make it difficult to determine the possible effects of distress.

When a whole community has experienced profound distress or maltreatment,
it complicates things, too.
Defining the types of distress, and their duration and/or chronicity,
would be extremely important,
as would looking at mitigating factors.

Lunacie
04-07-14, 01:52 PM
I think emotional distress is a primary factor.

How do you rule out the obvious emotional distress?


Peripheral

WHERE did I "rule out" emotional distress?



As I posted on your other recent thread, research indicates that the cause of ADHD seems to be 80% genetic and 20% environmental.

To me, that makes heredity the primary factor, and other factors such as distress secondary factors.

mildadhd
04-07-14, 01:56 PM
To see if emotional distress is a primary factor,
you could compare First Nations children from this community,
with and without ADHD symptoms,
to see whether those with ADHD
were more likely to have experienced emotional distress at an early age
(or have parents/caregivers who experienced emotional distress)
than those without ADHD.

Or, you could follow kids from birth
(or mother becoming pregnant)
until age 12 or so and document stressors
and presence or absence or degree of ADHD symptoms.

In both cases, you'd also need to consider
whether or not the parents had displayed symptoms of ADHD as well,
consider genetic heritability,
and tease out whether associated issues (like smoking or drug use)
might also affect the children's ADHD symptoms
in ways that make it difficult to determine the possible effects of distress.

Thanks, I appreciate the guidance and ideas to work on.

I don't think there is very many aboriginal families that are not emotionally affected in some way, by residential school type distress.

Some of the schools where open til 1990's, I know people who went to those "schools" and other "schools" across Canada.

There are also many other emotional distressful factors, residential school being among the worst and wide spread, from coast to coast.

See Canadian Government Residential School Apology video.

To avoid political topics, I picked this one because the government acknowledges the harm and the emotional pain.

Easier to focus on the topic of early development and emotional distress. (and hard to ignore)

There are lots of studies to show the affects of eustress and distress on the developing brain, affecting areas like the PFC.

I think it is best if I make a reference list of some studies, to easier address the OP topics.

If anyone has any research to back up any idea how the physiology of emotional distress has been ruled out, would be appreciated.

Thanks for your help Namazu.


Peripheral

namazu
04-07-14, 02:15 PM
Thanks, I appreciate the guidance and ideas to work on.

I don't think there is very many aboriginal families that are not emotionally affected, by residential school.

Some of the schools where open til 1990's, I know people who went to those schools.

I know people from many different nations across Canada, and United States.

There are many other emotional distressful factors, residential school being among the worst.
Yes, this is a sad chapter in both of our nations' histories, and has had a profound impact on Native American communities.

But if this kind of distress were a primary factor in causing ADHD,
wouldn't we expect a higher prevalence of ADHD in these communities?
(As you said, there are not very many aboriginal families who weren't emotionally affected by residential schools --
and, I would add, other forms of maltreatment or disadvantage.)
If everyone were exposed to distress, and distress were a primary factor causing ADHD,
then why does the majority of the population lack ADHD?
So we need to start looking into other factors as well.
It doesn't mean that distress is unimportant,
nor that distress couldn't contribute to ADHD,
but it doesn't explain why
some people in the population have ADHD and others do not.

So, as I suggested above, we would need to figure out
whether there were different types or levels of distress
or mitigating factors or other predisposing factors
that help explain why,
in the presence of widespread stressful experiences,
some people ended up with ADHD and others did not.

(The same would apply to adoption studies,
since most mothers who put their children up for adoption
experience a great deal of stress,
and depending on the circumstances of the adoption,
the child may also experience distress.
But not all adoptees have ADHD.
So we'd need to do more work to figure out
what distinguishes adoptees who develop ADHD from those who do not?)

There are lots of studies to show the affects of eustress and distress on areas like the PFC.

I think it is best if I make a reference list, because to easy address the topics.
I agree that these studies are important,
and may be relevant to ADHD
as well as to other conditions, like PTSD, anxiety, and depression.
But it will be tricky, given how little we understand
about how different parts of the brain work, and work together,
and the mechanisms underlying ADHD,
to pin down the exact causes.

mildadhd
04-07-14, 02:48 PM
I am not saying emotional distress is the only factor, I think it is a primary factor, emotional sensitive temperament, being another primary factor.

I have never ignored genetic predisposition.

That has always been my opinion.

I think everyone agrees that ADHD is multifactoral.(meaning there is more than one cause)

I think aboriginal people being referred to, have a higher rate of ADHD and commorbidities, not because they are any different.

But because they have experienced more emotional distress, for generations.

Than average. (not to say that some other people have not experienced the similar levels of terrible distress).

I have posted similar research topics about the effects of emotional distress on particularly sensitive mothers and infant, (pre and post natal) during 9/11 and also Holocaust survivors and families.

Nobody disagreed.

I have met elders, who where taken away from their families as children, that will not go and claim thousands of dollars of residential school apology settlement money,

because it is to hard emotionally to discuss publically, which they are required to do, to be eligible.

The fact is emotional distress has never been ruled out.

And there is lots of evidence that prenatal and post natal emotional distress has a negative impact on early childhood development.

I need to organize a reference list that I could point to.


Appreciate your interest, I will find research to support my opinions.


Peripheral

mildadhd
04-07-14, 03:07 PM
Anxiety, Depression and Addiction, are the three most common ADHD commorbidities.

Here is a great video with basic biological references.

(Dr.Mate has ADD)

http://www.youtube.com/watch?v=BpHiFqXCYKc

namazu
04-07-14, 05:18 PM
I am not saying emotional distress is the only factor, I think it is a primary factor, emotional sensitive temperament, being another primary factor.

I have never ignored genetic predisposition.
I know you are including genetic predisposition, among other factors.

I think aboriginal people being referred to, have a higher rate of ADHD and commorbidities, not because they are any different.

But because they have experienced more emotional distress, for generations.

Than average. (not to say that some other people have not experienced the similar levels of terrible distress).
I agree that aboriginal populations have been subject to conditions and attitudes that have caused great emotional distress,
and I agree that this distress (along with other socioeconomic factors) contributes a lot to mental health problems in native populations.

But I wonder if I was unclear in my question above:

I agree with you that emotional distress could be a contributing factor to the development or worsening of mental health issues, possibly even including ADHD.

But what I was wondering was:

If the entire population was subject to high distress, as you said,
and distress is a "primary cause" of ADHD,
then why do only 22.7% of the children in the population
(which is quite high, but still a minority)
show evidence of ADHD?

(And I will point out, because I know you will if I don't,
that the same could be said about individual gene variants associated with ADHD,
which thus far have not been shown to be necessary or sufficient for ADHD in most cases,
and I think this is something that researchers working on genetic causes of ADHD will have to explain.)


...Or maybe I'm not understanding what you mean by "primary factor". :scratch:

Could you please explain more what you mean by "primary factor"?

Is a "primary factor" one that is necessary to cause ADHD?

Is a "primary factor" one that is sufficient to cause ADHD?

Is a "primary factor" one that is present in a majority of cases of ADHD?

Is a "primary factor" just one that may be important in some cases of ADHD?

Or do you mean something else by "primary factor"?



And there is lots of evidence that prenatal and post natal emotional distress has a negative impact on early childhood development.
Yes, there is. (Though actually some studies suggesting that maternal emotional stress may, in some cases, be associated with *positive* development. Weird, huh?!)

mildadhd
04-07-14, 08:20 PM
I know you are including genetic predisposition, among other factors.


I agree that aboriginal populations have been subject to conditions and attitudes that have caused great emotional distress,
and I agree that this distress (along with other socioeconomic factors) contributes a lot to mental health problems in native populations.

But I wonder if I was unclear in my question above:

I agree with you that emotional distress could be a contributing factor to the development or worsening of mental health issues, possibly even including ADHD.

But what I was wondering was:

If the entire population was subject to high distress, as you said,
and distress is a "primary cause" of ADHD,
then why do only 22.7% of the children in the population
(which is quite high, but still a minority)
show evidence of ADHD?

(And I will point out, because I know you will if I don't,
that the same could be said about individual gene variants associated with ADHD,
which thus far have not been shown to be necessary or sufficient for ADHD in most cases,
and I think this is something that researchers working on genetic causes of ADHD will have to explain.)


...Or maybe I'm not understanding what you mean by "primary factor". :scratch:

Could you please explain more what you mean by "primary factor"?

Is a "primary factor" one that is necessary to cause ADHD?

Is a "primary factor" one that is sufficient to cause ADHD?

Is a "primary factor" one that is present in a majority of cases of ADHD?

Is a "primary factor" just one that may be important in some cases of ADHD?

Or do you mean something else by "primary factor"?



Yes, there is. (Though actually some studies suggesting that maternal emotional stress may, in some cases, be associated with *positive* development. Weird, huh?!)

Good Question.

Mathematically, it seems impossible for there to be only one cause/factor, to me.


I don't think its gene or environment.

I think it is gene and environment. (at least 2 factors required )


I think Bertrand Russel was write.

G can be equal to E, if and only if , G is not equal to itself.





Peripheral

namazu
04-07-14, 08:43 PM
Mathematically, it seems impossible for there to be only one cause/factor, to me.


I don't think its gene or environment.

I think it is gene and environment. (at least 2 factors required )
I agree.

So, could you please explain what you mean by "primary factor"?

(You used the term, but I don't know what you meant by it, so it would be helpful to me if you could explain.)

mildadhd
04-07-14, 09:45 PM
I agree.

So, could you please explain what you mean by "primary factor"?

(You used the term, but I don't know what you meant by it, so it would be helpful to me if you could explain.)

Decisive factors.

Factors required for epigenetic expression.

Environment on top of the gene.





Peripheral

SB_UK
04-08-14, 05:30 AM
Pity we can't assess ADHD on Mount Athos - a random population drawn from the planet.

No emotional distress suffered by any of the monks.

There won't be /any/ ADHD there.

Conclusion ??

emotional distress is a primary factor.Decisive factor.

SB_UK
04-08-14, 06:24 AM
Simplify - test for ADD in any monsastery/nunnery - would probably be enough.

The expt. is easy to do - you won't find any there - at least if the monks/nuns are secure enough not to need to worry about securing money for survival.

Athos is a better expt. - any monastery (nunnery) though should do.

Preferably locally self-sufficient - that is no need to exchange money with any other agent -for survival.

daveddd
04-08-14, 06:36 AM
WHERE did I "rule out" emotional distress?



As I posted on your other recent thread, research indicates that the cause of ADHD seems to be 80% genetic and 20% environmental.

To me, that makes heredity the primary factor, and other factors such as distress secondary factors.

i don't think this proves what you would like it to

certain PDs have 60% genetic factors, but still need an interaction to develop

your statement states 80% of people with adhd have susceptible genes

it does not rule out an interaction

I'm not saying i know what it is, but its a common mistake to assume those numbers rule out interaction

Lunacie
04-08-14, 11:47 AM
i don't think this proves what you would like it to

certain PDs have 60% genetic factors, but still need an interaction to develop

your statement states 80% of people with adhd have susceptible genes

it does not rule out an interaction

I'm not saying i know what it is, but its a common mistake to assume those numbers rule out interaction

I was NOT saying that 80 out of 100 people get ADHD from inherited genes

while 20 out of 100 people get it from environmental factors.



Research says the largest factor in any person having ADHD is genetics.

The environment plays a smaller role in that person having ADHD.

Both are factors, but one has a larger role in determining the outcome.

Lunacie
04-08-14, 11:53 AM
Pity we can't assess ADHD on Mount Athos - a random population drawn from the planet.

No emotional distress suffered by any of the monks.

There won't be /any/ ADHD there.

Conclusion ??

I don't agree that none of the monks (or nuns) in a closed society would have ADHD.

Chances are that the symptoms would be less evident in that environment.


I don't buy your idealized vision of the monastical society. It's still a social situation.

mildadhd
04-08-14, 01:14 PM
Focusing on OP, nobody can deny the misery and sustained anxiety, experienced by aboriginal caregivers and aboriginal children.

From the ground up, basic emotion genetic systems/circuitry, existing in all humans, interacting with the emotionally distressful environment. (for generations)

I know people, who in early childhood where taken far away from their families, forced to attended these "schools" for 10 years, without going home, or seeing their families once.


Children at the time.



Consider, for example, the misery of sustained anxiety, an expression of the FEAR system.

Arousal of the FEAR system eventually leads to excessive production of cortisol.

Under optimal conditions when an animal is afraid, the secretion of cortisol mobilizes glucose as an energy supply for the skeletal muscles

in case the animal decides to flee.

In this way, cortisol secretion is beneficial.

However, excessive secretion can begin to damage the body if elevations are sustained for too long.

Normally when cortisol has circulated through the blood back up to the brain, the paraventricular nucleus (PVN) of the hypothalamus exerts an inhibitory effect

that stops further release of cortisol.

If, however, a person or animal is subjected to an excessive amount of stress--when they are chronically frightened or anxious--the PVN may not be able to stop

the production of cortisol.

Panksepp/Biven, "The Archaeology of Mind", P xii.

TygerSan
04-08-14, 02:03 PM
The Conner's rating form was developed in the US, majority population. That means that it was not normed for Aboriginal children.

Part of the difference is likely to be cultural (be that because of the ruralness of the school, or the population of the school).

Performance on the SAT in the US tends to be higher among those of higher socioeconomic status. Part of that has to do with access to resources (including test prep).

There is also the concept of stereotype threat, in which drawing attention to ones minority status and supposed inferiority with regards to the majority (ethnicity, race, gender, whatever) decreases academic performance.

http://www.reducingstereotypethreat.org/definition.html

In other words, "distress" in terms of physical effects on an individual may be completely trumped by "distress" of a different type. And while societal/institutional "distress" contributes greatly to individual "distress", I think it is also important to note that the societal aspect alone can lead to dangerous and inaccurate conclusions about a population.

SB_UK
04-08-14, 03:38 PM
Consider, for example, the misery of sustained anxiety, an expression of the FEAR system.

Arousal of the FEAR system eventually leads to excessive production of cortisol.

Under optimal conditions when an animal is afraid, the secretion of cortisol mobilizes glucose as an energy supply for the skeletal muscles

in case the animal decides to flee.

In this way, cortisol secretion is beneficial.

However, excessive secretion can begin to damage the body if elevations are sustained for too long.

Normally when cortisol has circulated through the blood back up to the brain, the paraventricular nucleus (PVN) of the hypothalamus exerts an inhibitory effect

that stops further release of cortisol.

If, however, a person or animal is subjected to an excessive amount of stress--when they are chronically frightened or anxious--the PVN may not be able to stop

the production of cortisol.

Of key importance.

SB_UK
04-08-14, 03:41 PM
Close connection between ADHD and eg asthma:
http://www.ncbi.nlm.nih.gov/pubmed/16823718
Cortisol resistance in conditions such as asthma



Cortisol resistance -- from chronic exposure to (di)stressor.

-*-

The diseases of 'Western' living are all due to the distress of Western living.

Solution ?
Equality.
[Discard money/law]

SB_UK
04-08-14, 03:46 PM
Close connection between ADHD, asthma and eg obesity:
http://www.ncbi.nlm.nih.gov/pubmed/19850009
Comparison of the anorexigenic activity of C[ortisol]RF family peptides.

CRF resistance -> obesity.

SB_UK
04-08-14, 03:49 PM
Close connection between ADHD, asthma, obesity and self-medication (drugs of abuse):
http://www.ncbi.nlm.nih.gov/pubmed/24456850

Corticotropin releasing factor: A key role in the neurobiology of addiction.

mildadhd
04-08-14, 04:19 PM
The Conner's rating form was developed in the US, majority population. That means that it was not normed for Aboriginal children.

Part of the difference is likely to be cultural (be that because of the ruralness of the school, or the population of the school).

Performance on the SAT in the US tends to be higher among those of higher socioeconomic status. Part of that has to do with access to resources (including test prep).

There is also the concept of stereotype threat, in which drawing attention to ones minority status and supposed inferiority with regards to the majority (ethnicity, race, gender, whatever) decreases academic performance.

http://www.reducingstereotypethreat.org/definition.html

In other words, "distress" in terms of physical effects on an individual may be completely trumped by "distress" of a different type. And while societal/institutional "distress" contributes greatly to individual "distress", I think it is also important to note that the societal aspect alone can lead to dangerous and inaccurate conclusions about a population.


Why would the tests not work the same for all humans?

If we focus on studying the effects of emotional distress on brain development, from the ground up, helps avoids complex cognitive conflicts.

I am sure that all humans in general are born with the same brain and basic genetic emotion circuitry, and would experience the same emotional distress, if exposed to the same circumstances for generations.

I see things are slightly better in Canada, since the PM and others, made the apology.

But like everyone suffering with ADHD would know, after the PM apology, the ADHD and other effects of emotional distress, do not magically go away.




Peripherals

namazu
04-08-14, 05:25 PM
Why would the tests not work the same for all humans?
This is a good question.

A lot of tests -- even some biological / lab tests -- don't perform the same in different populations, and there are lots of reasons.

As a sort-of-ridiculous, but illustrative example:
if you develop a lab test for testosterone levels,
but your study sample includes only 20-30 year old men,
and so you base what's supposedly "normal" on only men,
and then you use this same test with the same norms in women,
or men above age 70,
or prepubescent boys,
most of them will look "abnormal", even though the lab results give you a number that's correct.
But that's not because their testosterone levels are actually "abnormal",
it's just that your test wasn't designed with those populations in mind,
so what you're calling "normal" (for 20-30 year old men)
doesn't really apply to these other populations (women, older men, boys).

The same holds true for behavioral rating scales.

There's a lot of work that goes into figuring out if a test measures what you want it to measure,
without measuring what you don't want it to measure.

And a lot of work also goes into figuring out
whether what's "normal" in the population you looked at is "normal" in other populations.

For example, in some cultures, it is considered rude to interrupt and question someone who's speaking,
while in other cultures, interrupting a speaker to ask a questions may be a perfectly socially-acceptable way to interact.

If you design a survey that asks teachers whether students interrupt often or not,
then you may find that very few interrupt in one setting, while in another culture, many students interrupt.
If interrupting is part of the definition of the disorder (such as ADHD),
then in some settings, more students may show "symptoms" -- even if what they're doing isn't abnormal for their cultural context.

In the case of Conners' rating scale for ADHD,
here are a few handsful of papers that look at how it performs in different populations (http://www.ncbi.nlm.nih.gov/pubmed/?term=conners+rating+validity).

I think this is why the authors of the study conclude that their results suggest
"either a high prevalence of ADHD in Aboriginal children or unique learning and behavioral patterns in Aboriginal children that may erroneously lead to a diagnosis of ADHD if screening questionnaires are used".

In other words, they don't know for sure
if the reason their screening flagged 22.7% of kids as showing ADHD-like behaviors
is because that many kids actually have ADHD,
or because there are other factors, like possibly cultural norms,
or educational design issues,
that are affecting kids' observed behaviors in this community.

Sorting that out would require additional investigation.

I am sure that all humans in general are born with the same brain and basic genetic emotion circuitry, and would experience the same emotional distress, if exposed to the same circumstances for generations.

I see things are slightly better in Canada, since the PM and others, made the apology.

But like everyone suffering with ADHD would know, after the PM apology, the ADHD and other effects of emotional distress, do not magically go away.
I agree that humans subject to great distress are at risk for stress-related adverse outcomes, including mental health problems.

But I think there are more factors involved, too.

There are other groups who have experienced temporary or long-term oppression and hardship, but don't necessarily have higher-than-"normal" rates of ADHD.

There are other long-term socioeconomic factors,
often environmental exposures (for many aboriginal populations in North America, lead and mercury exposures have been historically high),
that also probably play a role.
Same with smoking -- though there's a chicken-and-egg argument to be made about whether maternal smoking can lead to ADHD, or ADHD leads to maternal smoking, or both.

For some examples, you could look at this paper (http://www.ncbi.nlm.nih.gov/pubmed/23008274)or this paper (http://www.ncbi.nlm.nih.gov/pubmed/23916943)
focusing on Inuit populations in Quebec (different from the population in Alberta, I know) and environmental toxins.

So I'm not saying that aboriginal populations are inherently more vulnerable to ADHD,
nor that aboriginal populations respond worse to stress than other populations,
because you're absolutely right that being subject to discrimination, family separation, and human / civil rights violations could leave lasting scars on anyone.

But I do think that at least some aboriginal populations have been subject to a variety of conditions (both emotional and otherwise)
that may be contributing to a higher-than-expected prevalence of ADHD-like behaviors.

(...If the screening test is really picking up what we think of as ADHD in this population, and not mislabeling some kids because of differences in cultural norms, educational needs, or other factors.)

Dizfriz
04-08-14, 06:21 PM
i don't think this proves what you would like it to

certain PDs have 60% genetic factors, but still need an interaction to develop

your statement states 80% of people with adhd have susceptible genes

it does not rule out an interaction

I'm not saying i know what it is, but its a common mistake to assume those numbers rule out interaction
Dave, I am going to try to write something up on heritability but for now some comments:

Heritability is an abstract statistical measure which concerns how big a factor genetics are playing in differences in ADHD with populations of people. It says nothing about the individual. No cause is implied, it is strictly statistical based on the pattern of how the characteristics are inherited and says nothing about the genes involved.

Heritability is defined as the proportion of phenotypic variance attributable to genetic variance. It is an abstract statistical concept that only applies to populations and not to individuals.

The two factors usually examined are heritability and environmentability again both abstract in nature. Although other factors can be examined, these are the two usually involved in this kind of research so interaction, as I understand it, is not really covered very much and is not ruled out nor is it ruled in. Perhaps it is handled under environmentability but I really don't know.

If anyone wants to look at this a little more deeply, here is an article along with the math:
http://en.wikipedia.org/wiki/Heritability

I think heritability is misunderstood fairly often so I will try to come up with something reasonably soon. I am going to have to do some research since it has been many moons since I had stat and I have slept many times since then, sometimes soundly. I have no intentions of tackling the math. Been there, done that and have no interest in it.

Dizfriz

daveddd
04-08-14, 06:24 PM
something can be 100% heritable and still only be present with a environmental "activator"

correct?

daveddd
04-08-14, 06:30 PM
another question would be , 100% of people with the genes don't have the disorder, right?

Lunacie
04-08-14, 06:43 PM
something can be 100% heritable and still only be present with a environmental "activator"

correct?

A lot is known about the genes that are responsible for inheriting eye color.

What environmental "activator" do you think would switch on one color rather than another?

daveddd
04-08-14, 06:44 PM
A lot is known about the genes that are responsible for inheriting eye color.

What environmental "activator" do you think would switch on one color rather than another?

who's talking about eye color?

we're talking about mutations , not even in the same ballpark

mildadhd
04-08-14, 06:52 PM
The areas of the brain involved with ADHD develop in interaction with the environment.

I don't think we are talking about mutations.

I do think we are talking about epigenetics.


Peripheral

Dizfriz
04-08-14, 06:57 PM
who's talking about eye color?

we're talking about mutations , not even in the same ballpark
It is very probable that blue eye color in humans is due to mutation.

In 2008, new research suggested that people with blue eyes have a single common ancestor. Scientists tracked down a genetic mutation that leads to blue eyes. "Originally, we all had brown eyes," said Eiberg. http://en.wikipedia.org/wiki/Eye_color

Dizfriz

Amtram
04-08-14, 07:07 PM
It is incorrect to assume that every difference among humans is caused by a mutation. Most characteristics already exist in the genome and are simply present or absent because they were in the parents' chromosomes and the genetic combination caused the characteristic to be expressed.

It's also entirely likely that a common characteristic in a group that is genetically homogeneous and geographically isolated is a perfectly normal heritable trait.

Lunacie
04-08-14, 07:07 PM
It is very probable that blue eye color in humans is due to mutation.

http://en.wikipedia.org/wiki/Eye_color

Dizfriz

Thanks, very interesting.

Wilson's disease involves a mutation of the gene coding for the enzyme ATPase7B, which prevents copper within the liver from entering the Golgi apparatus in cells. Instead, the copper accumulates in the liver and in other tissues, including the iris of the eye. This results in the formation of Kayser–Fleischer rings, which are dark rings that encircle the periphery of the iris.

From Dizfriz's link.

Andi
04-08-14, 07:50 PM
Closed for review.