A blood test may help the diagnosis and treatment of depression
economist.com
economist.com
The point is "depression" or "PTSD" probably don't exist among many others. There are perhaps dozens or hundreds of unique conditions currently lumped together because they present in vaguely similar ways - the good news is that we are making progress towards much more arguably "real" understandings, the bad news is we're still quite far away from diagnosing mental conditions with the same specificity we can diagnose cancers or viruses.
That’s generally true of diagnosis when we don’t understand the mechanism, and since where we do understand the mechanism we treat that as a reason to move the thing-with-behavioral-symptoms out of psychology and into some other medical domain, so its essentially an irreducible problem with psychology.
And as for computer aid in this area, it would be awesome, but I fear we are still far away from it, especially since diagnosis is an interactive, continuous process, and is not separate from treatment. The patient presents with some symptoms a history and a current course of treatment, you order some tests and may even prescribe some medication for a preliminary diagnosis, then you wait and adjust as new information comes along. I'm not sure current approaches in machine learning deal very well with this type of process.
Obviously I'm not a doctor and can only assume that this is like somebody telling me "Debugging is easy, you just set a breakpoint..." But I'd be curious to know more about why this approach failed.
I also wonder how well the inference algorithms would actually perform with the scale of facts you would need to add.
That is true. The groupings persist because they are useful in facilitating communication regarding potential complications, prognosis, and patterns of response to treatments.
People seem intent on throwing away the above utility with a backhanded “but that’s not the Real Diagnosis.” It’s not, but within the limitations of our current understanding of neurology, it’s the best we have come up with so far (allowing for some limitations due to the pace of spread of innovations, politicking, etc.)
> The groupings persist because they are useful in facilitating communication regarding potential complications, prognosis, and patterns of response to treatments.
These are reasons, but they're a distant second. Mainly, they persist because those groupings - diagnoses, in other words - have become necessary for billing. The DSM, for instance, is an economic document, not a scientific one. For most people, it sits on a shelf, gathering dust.
As for "the best we've come up with so far", you'd perhaps be interested to learn how often the decisions about these groupings are made because of politics and economics, and not by science [1].
[1] https://www.amazon.com/They-Youre-Crazy-Paula-Caplan/dp/0201...
One sees this in a bizarre number of fields, that specialists act as though the classifications actually be as rigid and objective as in, say, physics, and that something objectively is or is not something, and then debate it.
I've actually read some debates between linguistics that are quite passionately debating whether something is an allophone of the same phoneme, or a different phoneme altogether, and I do not find such distinctions to be all that objective as the language they used suggests.
To know a thing's name is to have power over it.
From ancient mythos to modern specialists and especially philosophy, naming things gets a whole lot of focus. It does because it is terrifically useful! Naming, separating, making distinctions, this is an essential part of understanding.
However a whole lot of these kinds of debates don't acknowledge what kind of a debate they are actually happening. Is the subject of debate the limits of where a definition matches and were it doesn't? Is it whether the subject fits within already agreed limits? Is it really about an unspoken assumption that differs between the parties arguing? Many also don't address the quality of the definition. Is it a useful definition that represents defensible differences between "has this name" and "doesn't have this name" or is it an entirely arbitrary classification (say, look at the color spectrum and define areas which are red and which are orange; now zoom in on a boundary between the two, is there any defensible reason why the border should not be moved slightly to add one color to red? No, probably not)
> I've actually read some debates between linguistics that are quite passionately debating whether something is an allophone of the same phoneme
In this example are they really arguing about the something in question or are they arguing about the definition of "allophone" without realizing it. The followup question is "what is the reason why this edge case is relevant?" and "if this edge case isn't relevant, is the term 'allophone' even useful?"
I do not believe they are arguing about the definition either, nor do I believe that the classification has any use as whichever way it falls changes nothing.
Linguistics is a field plagued by classification for it's own sake, as many others are. Objects are classified but no conclusions can be drawn from the classification. — perhaps it is but simply a form of mental file organization.
https://www.verywellmind.com/can-psychologists-prescribe-med...
Such markers have long existed and been found. This wording suggests that this is the first attempt.
The markers are always only correlative, and obviously it won't happen that, if a patient show the markers, but otherwise show no subjective, he'll be diagnosed with depression, or vice versā, denied such a diagnosis, if he show the symptoms, but not the markers.
> Together, these 13 RNA markers form the basis of a blood test that can not only diagnose depression,
“diagnose”? I doubt that it will replace subjective diagnosis for the aforementioned reason. — the subjective diagnosis will remain the final judgement for a time long to come.
[Citation needed]
That seems like a bold claim relative to our current level of understanding.
If there is one thing that we do know it is that depression, say, is multifactorial and complex. In very few cases are the reasons only biological (but they do exist). See e.g.
When I realized this I didn’t know how much my environment was affecting my bipolar disorder. Buy matching my nature in my nurture I’ve come along way and getting off of almost all my medications.
Edit: forgot my biology, testing for levels of RNA is probably pretty close to testing protein production.
The way I see this is that it might be one of those tests that, if they come back positive, indicate that further analysis should be made. A general practitioner might ask for this test and then recommend to the person to see a specialist.
What seems clear is that in a lot of cases depression seems to be a normal reaction to worsening life conditions and not merely a brain chemicals imbalance. So I think it's wise to remain careful around what can be considered a depression and whether it should be considered a symptom or a disease.
https://www.theguardian.com/society/2018/jan/07/is-everythin...
You cannot have a change in mood with out changes in brain catecholamines. Catecholamines are physical.
They would both be measurable in physical terms, but that doesn't mean that they have to both be exactly the same thing. IF this vague notion were correct, it could mean that there could be separate diseases like "physical depressions" (that is, various defects of the body's hardware that cause abnormal amounts of certain neurotransmitters to be present in the brain, influencing thought that way) and "psychological depressions" (various mistakes in the thought process/software that cause problems with motivation/emotions/etc, that themselves also result in certain neurotransmitters being present in abnormal amounts).
And both the assumption and conclusions are bizarre.
There is no such distinction in the brain and the distinction in, physical man-made, hardware is also not so clear.
How do you know this? What else would the brain be if not a computer, and if you agree that it is a computer, why do you believe it doesn't have some equivalent of "software"?
> the distinction in, physical man-made, hardware is also not so clear
Sure, the distinction is somewhat fuzzy, though there can be clear cut cases as well.
Because not all computers have this distinction, the first man-made computers did not have this distinction and the distinction still isn't that clear.
“software” is simply the part the end-user is expected to be able to change. The F.S.F. simply defines it as everything stored in writable memory, but the distinction between writable and nonwritable memory is not even so clear.
The human brain doesn't have a distinction between writable and nonwritable memory, and memory is implemented in circuitry itself.
One can build a computer even today that has no distinction between software and hardware.
Another piece of evidence that suggests to me that certain psychiatric conditions originate not in the physical brain itself but more in the "computation" (what I called a software error earlier) is the way people can be trapped into cults or other abusive relationships, where they start exhibiting signs of mental illness without any direct physical changes (that is, no diet changes, no physical violence, no irradiation etc.).
The reason why I consider this distinction is important is that, if I am right, then there must be psychiatric conditions that should be fixable through discussion and improvements in thinking (therapy), and there must also be psychiatric conditions that can't be fixed in this way. We know for sure that the second category exists, as some psychiatric symptoms are the result of tumors in the brain and elsewhere in the body; the first category is slightly less clear, thought therapy is definitely an important part of many treatment regimens, with clinical data backing up its use.
The biggest problem today is that we can't reliably tell, in most cases, which type of disease you may have, and so which approach is appropriate.
“back pains” is not a physical condition; there is a plethora of different physical conditions that can result into such superficially similar symptoms and this is the flaw psychiatry as a discipline is often criticized of, the assumption that an approach which assumes a defining cause necessarily has merit absent any evidence of such a defining cause.
What is a 'normal' level of catecholamines?
Not disagreeing that the mental/physical dichotomy is arbitrary.
What is a normal level? well, you know it when you feel it. There is no normal level, I get what you mean, depression exists for a reason. As does mania. These are healthy responses when we come into contact with an external stimuli. The issue is with mental illness, not mental health. With mental illness the changes happen with no apparent environmental stimulus.
Somebody else stated it already better than I could: We do have a number of biomarkers for depression, the problem is they only correlate with the disease, so asking you how you feel in a structured way is still more indicative.
Even the serum tests for catecholamines vary so much that you have to take them specific times of the day. And it can in no way diagnosis depression or any other mood disorders through those test. There Are no biomarkers for depression right now that are widely tested or even tested minimally. I know, I asked for them all the time because I have bipolar disorder.
However it's not helpful in terms of diagnosis and treatment, which is fundamentally different in many ways compared to physical conditions - and stigma is often a result of people no understanding the difference.
To make a really simplified example: If you break your leg, a doctor will do a test, an x-ray say, recognise the leg is broken and interfere directly in one way or another with the physical system that is your body. The conscious you is not a part of this process (this is a simplified example, it does make some difference).
If you 'break your mind,' again very simplified, because you are treated like sh*t at work, your parent dies, you are genetically predisposed and have no social net, and as a result develop depression, there is no (physical) test. The conscious you is a central part of the treatment. It is even thinkable to not treat the physical you but target your environment instead.
Again this is a simplified example with shortcomings. Also having read your replies I believe you wanted to simply highlight that the distinction physical/mental is arbitrary and it is.
Just to make a distinction here. Worsening life conditions will also cause a "chemical imbalance" so it would look the same. The problem with people who have a Mental Illness is that the mood changes appear without any "known" life changes, which makes it harder to find the cause.
For me it is diet and environment that seem to have caused most of my issues.
Depression is a symptom, always, since it is caused by something more fundamental.
I would say that they need to do an RNA test and a Genetic Test as well.
I have Bipolar Disorder and even I go through periods of remission. Looking at genetics might give a better clue about how the trauma may effect a person long term.
They really need to figure out how to test for these catecholamines in the brain...
I'm not sure if I read this correctly, but part of their approach is to take biomarkers from suicide victims
The validation step 3 is usually done in an independent cohort of clinically severe subjects (or, in the case of suicide, a cohort of suicide completers).
https://www.nature.com/articles/s41380-021-01061-w
I have my genetics through 23andme and I have Bipolar Disorder. The one thing that stuck out at my in my genetics were my SNPs in SLC6A4, which is one of the markers they look at.
Le-Niculescu, H., Roseberry, K., Gill, S.S. et al.
Precision medicine for mood disorders: objective assessment, risk prediction, pharmacogenomics, and repurposed drugs.
Mol Psychiatry (2021)