Neurobiological Origin of Attention Deficit Disorder Discovered

[GYre0ePJhZ]

I came over this article which states that the biological origins of ADD have been confirmed. I must say I am not knowledgeable at all about ADD, but I am interested in it and I don't know what to think of it this study so I thought a discussion here could be helpful. This quote serve as a good starting point:

 

 

The superior colliculus is found in the midbrain and has many sensory- and motor-related functions. The researchers introduced a population of mice to a genetic mutation which doubled the connections between the retina and superior colliculus, creating visual hyperstimulation. Those with the mutation also had a superior colliculus with a buildup of the neurotransmitter noradrenaline, which is “fight or flight” molecule that increases heart rate and prepares the body to react to a stimulus.

 

So, they have found that giving a genetic mutation to mice brains had the following consequences:

• Visual hyperstimulation.
• Larger amounts of noradrenaline, a "fight or flight" molecule that increases heart rate and prepares the body to react to a stimulus.

I skimmed the comments (don't do that if you want to keep your sanity btw ) of this article and the sentiment seems to be that this study proves ADD is hereditary, that is, environment has nothing to do with it and people who get ADD are just unlucky in the same way people with Huntington's disease are.

 

While it certainly is an empirical question, I don't think this extrapolation is true. Firstly, there is the question of whether studies which provide knowledge about mice brains can be directly transferable to human brains. This does not necessarily follow for obvious reasons, but it can be an indication. Secondly, it does not explain why there have been many times more people diagnosed with ADD over the decades. Thirdly, it does not explain why some countries have more kids diagnosed than others. Fourthly, it does not explain why five times more boys than girls get diagnosed with ADD. Fifthly, while genetically induced mutations in mice can give physical changes in the structure and function of the brain it still is possible that epigenetics play a role here. That is, stimuli provided in the environment change the genetics of the kids, thus altering how the brain develops so that it is reflected both in the structure and function of the brain as well as in the resulting behaviors typical for ADD. I think point 2-4 can be explained by politics and incentive structures, but point one and especially point five are the most valid objections to a 100 % genetic explanation of ADD.

 

I often get the impression in the public discourse that the protection of parental figures and significant others in the upbringing bias people towards a predominantly genetic explanation of for instance ADD.

 

If we flip this around though, and find evidence for that ADD is caused by epigenetics, knowledge about brain structure and ADD can in the future turn out to be a very reliable tool for determining whether children who have symptoms associated with todays ADD-diagnosis have been abused.

 

Just some thoughts. What do you think?

[Prairie]

I like your line of inquiry because it seeks consistency in order to root out faulty reasoning. I'm not very optimistic and think it's environmentally caused in that the environment of society cannot tolerate people who don't operate with its dictates. Any human behavior at all can have some apparent biological cause found to be labeled as defective and thus serve as justification for forced drugging or whatever method of control is used.

[Tyler Durden]

Parents physically and verbally abuse children, they put them into schools where they are forced to perform random tasks regardless of whether they're even remotely interested in them, when they don't carry out these tasks in the way that teachers expect them to they are forced to take drugs, these drugs cause a whole variety of severe problems. So what can we do to make the situation better?

 

O wait, I know! We can torture mice!

[Wuzzums]

I'm more interested how those researchers managed to determine the following in the mice:

• Often fails to give close attention to details or makes careless mistakes in schoolwork, work, or other activities
• Often has difficulty sustaining attention in tasks or play activities
• Often does not seem to listen to what is being said
• Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (not due to oppositional behavior or failure to understand instructions)
• Often has difficulties organizing tasks and activities
• Often avoids or strongly dislikes tasks (such as schoolwork or homework) that require sustained mental effort
• Often loses things necessary for tasks or activities (school assignments, pencils, books, tools, or toys)
• Often is easily distracted by extraneous stimuli
• Often forgetful in daily activities 
• Hyperactivity evidenced by fidgeting with hands or feet, squirming in seat
• Hyperactivity evidenced by leaving seat in classroom or in other situations in which remaining seated is expected
• Hyperactivity evidenced by running about or climbing excessively in situations where this behavior is inappropriate (in adolescents or adults, this may be limited to subjective feelings of restlessness)
• Hyperactivity evidenced by difficulty playing or engaging in leisure activities quietly
• Impulsivity evidenced by blurting out answers to questions before the questions have been completed
• Impulsivity evidenced by showing difficulty waiting in lines or awaiting turn in games or group situations 

These are the DSM criteria for diagnosing ADHD. Either those researchers have an uncanny ability to communicate with mice, or they just messed around with some mice with the pretense that "it's for research" and flimsily linked it to ADHD to be more hip with the times.

Bad science really pisses me off. First off the title gives it away: "Neurobiological Origin of ADD". What does that even mean? Everything the brain ever does is neurobiological. Thought is fucking neurobiological !

[Pepin]

I think it is good to point out that though they induced these effects with genes, that does not imply that genes are the primary cause in humans. There may be many ways that an increase of these connections can develop.

 

Granted that this study is validated, I find it more likely to be a result of neural plasticity, that is that the brain wires itself in this way due to the environment. A child for instance who has to react according to visual stimuli immediately in early life will create more connections between those parts of the brain, and once these connections are made, they are very hard to reverse. I would suspect that there is a bit of a feedback loop where once this becomes the primary method of dealing with stimuli, it reinforces itself through inhibition of alternatives.

 

There are likely genes involved, though the question is to what degree?

 

I'm open to it being a completely genetic feature that is far more noticed in the modern age due to obvious reasons. For most all of human history, we were not really standing still that much, and if we were it was after an exhausting day of survival. I find it more likely that it is a combination.

[GYre0ePJhZ]

 

I'm not very optimistic and think it's environmentally caused in that the environment of society cannot tolerate people who don't operate with its dictates.

 

I'm curious what you mean by optimistic?

 

 

Bad science really pisses me off. First off the title gives it away: "Neurobiological Origin of ADD". What does that even mean? Everything the brain ever does is neurobiological. Thought is fucking neurobiological !

 

I share the anger of this whole travesty that is modern psychiatry. But I don't think this is reasonable, and I think it is worthwhile to pursue neurobiological knowledge: What I find valuable is not whether it origins in the brain or not, but where specifically can we point inside the brain and say that something origins there. Calling something "Bad science" is a very high stake claim since it is in the methodology one can find evidence of such. I can't see where you pointed to any methodological limitations except the problem with transferring knowledge about mice to humans which several posters here already have done, including the OP.

 

What I do think it gives basis for though is to say the title of the popular scientific article is imprecise, false, or not proven. The title of the actual journal article is "Defective response inhibition and collicular noradrenaline enrichment in mice with duplicated retinotopic map in the superior colliculus". And in the abstract of the journal article is says: "Our results suggest that structural abnormalities in the superior colliculus can cause defective response inhibition, a key feature of attention-deficit disorders".

 

I think you should change your assertion from bad science to bad journalism, which I would wholeheartedly agree with

 

 

I'm open to it being a completely genetic feature that is far more noticed in the modern age due to obvious reasons. For most all of human history, we were not really standing still that much, and if we were it was after an exhausting day of survival. I find it more likely that it is a combination.

 

While it was obvious for you, I was oblivious of that Thanks, interesting!

[JamesP]

The brain is organized in response to its environment. People are desperate to avoid environmental discussions as environment is something you can control.

[GYre0ePJhZ]

The brain is organized in response to its environment. People are desperate to avoid environmental discussions as environment is something you can control.

 

Yes, many of the people I have discussed these things with are very eager to put forward genetics and evolutionary knowledge, but I see it in their body language that they get uncomfortable the second I mention epigenetics, plasticity, child abuse etc.. And it gets downplayed or ignored. It is both fascinating and ridiculous to observe That said, knowledge about genetics and evolution are valuable so one knows potential limitations of environmental explanations. E.g. genetics of blue eyes.

[Prairie]

Avalanche, my "I'm not very optimistic" comment was about scientific study of ADD yielding any benefit to those labeled (by others or themselves). When the intent of people in general is to avoid seeing the massive mistreatment of people and instead find distracting explanations, better science will only make their job easier. That said I wish this thread had been able to stay more on your original line of examination.

[GYre0ePJhZ]

Avalanche, my "I'm not very optimistic" comment was about scientific study of ADD yielding any benefit to those labeled (by others or themselves). When the intent of people in general is to avoid seeing the massive mistreatment of people and instead find distracting explanations, better science will only make their job easier.

 

I think you have a really good point there, and I think I know what you mean. You are saying that scientific study of ADD won't benefit the labelled ones as long as it is used as distraction rather than something to accompany knowledge about the mistreatment of people? If this is your meaning I think you are right because there is already talk about developing new meds to cure the "root cause" of ADD as a result of this study.

[Wuzzums]

I share the anger of this whole travesty that is modern psychiatry. But I don't think this is reasonable, and I think it is worthwhile to pursue neurobiological knowledge: What I find valuable is not whether it origins in the brain or not, but where specifically can we point inside the brain and say that something origins there. Calling something "Bad science" is a very high stake claim since it is in the methodology one can find evidence of such. I can't see where you pointed to any methodological limitations except the problem with transferring knowledge about mice to humans which several posters here already have done, including the OP.

 

What I do think it gives basis for though is to say the title of the popular scientific article is imprecise, false, or not proven. The title of the actual journal article is "Defective response inhibition and collicular noradrenaline enrichment in mice with duplicated retinotopic map in the superior colliculus". And in the abstract of the journal article is says: "Our results suggest that structural abnormalities in the superior colliculus can cause defective response inhibition, a key feature of attention-deficit disorders".

 

I was a little impulsive (haha) in attacking the title of the article assuming it was the same as the actual study. Read the study, it was very grounded and didn't really try to make outlandish claims like article. From the conclusion:

"The behavioral and molecular changes in EphA3 mice including defective response inhibition and noradrenaline enrichment in the superficial layers of the SC phenocopy some of the symptoms observed in ADHD patients, specifically the adult and predominantly inattentive-type. (...) Our findings support the hypothesis that aduld ADHD patients present collicular hyperstimulation leading to the appearance of impulsivity and attentional impairments."

 

OK, so there's a link between TWO symptoms of ADHD and overstimulation of that part of the brain.

And also let's assume that mice and humans are exactly alike and we can extrapolate data from mice to humans with 100% accuracy.

And also let's assume that ADHD is a well established disease which stood up to the most rigorous of tests.

 

ADHD inattentive-type is defined in the DSM as having at least 6 of the following:

• Often fails to give close attention to details or makes careless mistakes in schoolwork, work, or other activities
• Often has difficulty sustaining attention in tasks or play activities
• Often does not seem to listen to what is being said
• Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (not due to oppositional behavior or failure to understand instructions)
• Often has difficulties organizing tasks and activities
• Often avoids or strongly dislikes tasks (such as schoolwork or homework) that require sustained mental effort
• Often loses things necessary for tasks or activities (school assignments, pencils, books, tools, or toys)
• Often is easily distracted by extraneous stimuli
• Often forgetful in daily activities

ADHD with hyperactivity/impulsivity traits is chracterised by at least 4 of the following:

• Hyperactivity evidenced by fidgeting with hands or feet, squirming in seat
• Hyperactivity evidenced by leaving seat in classroom or in other situations in which remaining seated is expected
• Hyperactivity evidenced by running about or climbing excessively in situations where this behavior is inappropriate (in adolescents or adults, this may be limited to subjective feelings of restlessness)
• Hyperactivity evidenced by difficulty playing or engaging in leisure activities quietly
• Impulsivity evidenced by blurting out answers to questions before the questions have been completed
• Impulsivity evidenced by showing difficulty waiting in lines or awaiting turn in games or group situations

So they managed to determine that 1/6 and 1/4 symptoms are correlated with brain changes. Fair enough, but what about the other symptoms required to diagnose ADHD? The language they use in the study is very careful to not make the outrageous claim the article does. Saying the cause of a disease is the same with the cause of a certain symptom of that disease is like saying the cause of flu is fever.

[GYre0ePJhZ]

I don't have anything to add to that, but I want to say that you made good arguments and objections! Thanks!