Psychiatry Research

[solumanculver]

Advertisement - Members don't see this ad

Hello,

I'm interested in studying the neurological bases of psychiatric disorders like Schizophrenia, Autism, and OCD. I'm considering applying to MD/PhD programs in 2008, but I'm not sure if I should. I'm a little concerned that the clinical description of these disorders, provided that the DSM-IV is the pinnacle of our descriptive knowledge so far, isn't biologically specific enough to really do research on these things on the molecular level. Isn't the first step in studying the etiology of these disorders to find some reliable correlations between symptoms and genes? It seems like we need a biological top-down approach to these disorders so that we ask the right questions before we answer them on the molecular/cellular level... and if that's the case, it seems like a PhD in neuroscience would not be as helpful as an MPH and access to a pool of patients and their genes... I'm not really sure. So I guess my question to you guys is, is the crucial area of psychiatric research still largely in epidemiology, or have the data come in and we're just waiting to find the broken neural pathway? Or, alternately, should I try to get an MPH or a PhD? Thanks for your help.

Soluman

 

[acf11]

I think you really need to consider what type of research you would be most happy doing. Epidemeology is quite different from "wet lab" work in, say, molecular genetics. Further, there is exciting work on the etiology of psychiatric disorders; David Lewis at Pitt is doing really interesting science about the cellular/molecular basis for schizophrenia. Search him on PubMed and you'll find a number of interesting reviews to give you a taste of what's out there. Hope this helps a bit.

 

[Vader]

There are a variety of ways you can approach research questions on these disorders: biochemistry, molecular biology, cell biology, genetics, neuroimaging, systems neuroscience, neuropsychology, symptomatology, treatment responses, etc. I suggest you read some review articles in these areas to get a better idea of the lay of the land.

For a very recent review/overview of schizophrenia related neurobiologic research:

Ross CA et al. 2006 Neuron 52, 139-153

 

[Hurricane]

Psychiatry is still rather young, as biomedical sciences go. The disorders in the DSM are syndromes not diseases - i.e. descriptions of patients who share a set of symptoms without regard to etiology. As it stands now, two people may meet the criteria for schizophrenia, yet have different underlying pathology. Some see this as a wide-open opportunity for research, others find it frustrating and imprecise. If you decide you're in the first group, then you need to figure out what kind of research you want to do, as others have said. Not what specific subject matter - what kind - epidemiology, genonics, systems/behavioral, molecular, imaging, etc. because they are very different from each other.

There is plenty of opportunity for large scale epidemiological and genomics studies, as well as basic work. As far as basic work goes, a PhD in neuroscience is absolutely useful for psychiatry research. Neuroscience is one of the most interdisiplinary of fields, and we need people working on the clinical side to help the basic scientists identify targets, as well as basic scientists to help guide the clinicians towards genes to look for, etc. And FWIW, the relatively new director of the NIMH has publicly stated that psychiatry research/drug development has been "backwards" for quite some time and needs to become more basic science driven.

Hope this helps. Happy holidays 🙂

 

[strangeglove]

Isn't the first step in studying the etiology of these disorders to find some reliable correlations between symptoms and genes?
Soluman

No, it isn't. Also, before you skip from genes to public health, consider cellular neuroscience, systems neuroscience, cognitive neuroscience, psychology, anthropology and philosophy - all PhD-granting areas that are highly relevant for understanding the human mind/brain and its relationship to psychiatric disorders. The DSM-IV is not a scientific tool. It is a convenience that allows for consistent billing for services. The best way to learn about the phenomenology of psychiatric disorders is to talk to patients. Then think about what is going on in their brains.

 

[Newquagmire]

I talked to some people in this field at my school and the general consensus was that "molecular psychiatry" seemed very promising but has generally turned out to be much more complicated than anyone expected.

 

[toby jones]

Cognitive Neuro-Psychologists work on the cognitive (and neurological) bases of psychiatric disorders such as Schizophrenia, Autism, and OCD.

Christopher Frith has done some good work on Schizophrenia (though admittedly he is more interested in the cognitive rather than neuropsychological level)

http://www.amazon.com/Cognitive-Neuropsychology-Schizophrenia-Essays-Psychology/dp/0863773346

I've just finished reading this:

http://www.amazon.com/Mind-Brain-Ne...ef=sr_1_1/105-9762512-8527646?ie=UTF8&s=books

Which is a little pop-sciencey... But the author is a psychiatrist who is interested in the neurological underpinnings for OCD including offering an account of how mindfulness meditation leads to changes in the 'OCD circuit'.

There has been a move within psychology to apply the methods of cognitive neuropsychology to psychiatric symptoms (hence a field of cognitive neuropsychiatry is emerging). They focus on symptoms (like delusions, hallucinations etc) rather than diagnostic categories endorsed by the present version of the DSM because they have some of the concerns you do. Of course the same problem has a tendency to re-emerge at the symptom level. The kind of research you are interested in (in my opinion) is required in order for us to come to more adequate diagnostic categories, however.

There is an Iceland genome project that may interest you (with respect to the genetics of schizophrenia). Google should help you out with finding the reference. I think a back and forth approach between a top down and a bottom up is what is required. Findings drive questions and questions drive studies which produces findings...

 

[strangeglove]

Cognitive Neuro-Psychologists work on the cognitive (and neurological) bases of psychiatric disorders such as Schizophrenia, Autism, and OCD.

Christopher Frith has done some good work on Schizophrenia (though admittedly he is more interested in the cognitive rather than neuropsychological level)

http://www.amazon.com/Cognitive-Neuropsychology-Schizophrenia-Essays-Psychology/dp/0863773346

I've just finished reading this:

http://www.amazon.com/Mind-Brain-Ne...ef=sr_1_1/105-9762512-8527646?ie=UTF8&s=books

Which is a little pop-sciencey... But the author is a psychiatrist who is interested in the neurological underpinnings for OCD including offering an account of how mindfulness meditation leads to changes in the 'OCD circuit'.

There has been a move within psychology to apply the methods of cognitive neuropsychology to psychiatric symptoms (hence a field of cognitive neuropsychiatry is emerging). They focus on symptoms (like delusions, hallucinations etc) rather than diagnostic categories endorsed by the present version of the DSM because they have some of the concerns you do. Of course the same problem has a tendency to re-emerge at the symptom level. The kind of research you are interested in (in my opinion) is required in order for us to come to more adequate diagnostic categories, however.

There is an Iceland genome project that may interest you (with respect to the genetics of schizophrenia). Google should help you out with finding the reference. I think a back and forth approach between a top down and a bottom up is what is required. Findings drive questions and questions drive studies which produces findings...

Hmm. You seem more thoughtful than the typical medical student or resident.

 

[solumanculver]

http://www.amazon.com/Mind-Brain-Neuroplasticity-Power-Mental/dp/0060988479/sr=1-1/qid=1168353358/ref=sr_1_1/105-9762512-8527646?ie=UTF8&s=books[/URL]

Which is a little pop-sciencey... But the author is a psychiatrist who is interested in the neurological underpinnings for OCD including offering an account of how mindfulness meditation leads to changes in the 'OCD circuit'.

Hi, thanks for your response. I've read that book as well, but I considered it to be more of a lay attempt to make a philosophical argument against materialism than a book about actual brain research. Something like a John Eccles approach of postulating functional gaps in the brain that can be filled in by an immaterial mind. I liked it, but I prefer to read philosophy from philosophers... As I recall the author actually threw in some anecdotes about how he was hanging out with David Chalmers, which to me, really made clear his purpose in the book.

This is exactly what I was getting at, as you pointed out. There is no conceptual difference between the definition of a syndrome and the definition of an individual symptom. If we wanted to research the genetic component of something like "delusions of thought-extraction" we would still have to invent a set of diagnostic criteria to decide whether or not a person actually had that delusion. It seems like, in order to study the neurological disorder underlying any given psychiatric symptom, you have to have a diagnostic description of that symptom... but that's exactly where the problem is, coming up with a meaningful diagnostic category.

It seems like, in order to explain the etiology of any disease, you first have to have a sufficiently fine-grained definition of what you're trying to explain. We couldn't, for instance, discover the underlying etiology of "the crazies", where "the crazies" is the group of all psychiatric disorders, because there is too much heterogeneity in the group to come up with any meaningful generalization. It's not that it's too difficult to do so, it's just conceptually impossible... kind of like discovering the chemical make-up of phlogiston.

So, just to clarify my original question, what I was really trying to ask was: Is there a sufficiently fine-grained definition of any psychiatric disorder to make studying the molecular/neurological causes even feasible, or does there first have to be studies in correlating different sets of symptoms to different sets of genes to come up with categories that are meaningful on the molecular level?

I guess that that is about as good an answer to my question as I could hope to get. As neuroscience finds more neural systems and subsystems, each of which can be defective, the field of diagnostic categories will open up until eventually any given disorder will have been reductively explained all the way down, at which point the criteria will have become sufficiently fine-grained to describe the syndrome... Thanks a lot, by the way for everyone's input.

 

[solumanculver]

Cognitive Neuro-Psychologists work on the cognitive (and neurological) bases of psychiatric disorders such as Schizophrenia, Autism, and OCD.

Christopher Frith has done some good work on Schizophrenia (though admittedly he is more interested in the cognitive rather than neuropsychological level)

http://www.amazon.com/Cognitive-Neuropsychology-Schizophrenia-Essays-Psychology/dp/0863773346

I've just finished reading this:

http://www.amazon.com/Mind-Brain-Ne...ef=sr_1_1/105-9762512-8527646?ie=UTF8&s=books

Which is a little pop-sciencey... But the author is a psychiatrist who is interested in the neurological underpinnings for OCD including offering an account of how mindfulness meditation leads to changes in the 'OCD circuit'.

There has been a move within psychology to apply the methods of cognitive neuropsychology to psychiatric symptoms (hence a field of cognitive neuropsychiatry is emerging). They focus on symptoms (like delusions, hallucinations etc) rather than diagnostic categories endorsed by the present version of the DSM because they have some of the concerns you do. Of course the same problem has a tendency to re-emerge at the symptom level. The kind of research you are interested in (in my opinion) is required in order for us to come to more adequate diagnostic categories, however.

There is an Iceland genome project that may interest you (with respect to the genetics of schizophrenia). Google should help you out with finding the reference. I think a back and forth approach between a top down and a bottom up is what is required. Findings drive questions and questions drive studies which produces findings...

Oh... I didn't realize that you were actually a philosopher. You know, I was considering applying to phd programs in analytic philosophy at one time. I decided to apply to medical school instead though... I guess it's because it's easier to be an amateur philosopher than amateur physician. It's also more legal... I've been looking for some good books/articles on the philosophy of psychiatry, do you have any recommendations?

 

[qtpai]

Oh... I didn't realize that you were actually a philosopher. You know, I was considering applying to phd programs in analytic philosophy at one time. I decided to apply to medical school instead though... I guess it's because it's easier to be an amateur philosopher than amateur physician. It's also more legal... I've been looking for some good books/articles on the philosophy of psychiatry, do you have any recommendations?

Concepts of Psychiatry by Nassir Ghaemi

 

[toby jones]

Here are some different levels of explanation:

Behavioural
Cognitive psychological
Neurological
Genetic
Environmental (incl social)

I'm interested in how causal mechanisms at each level inter-relate for modelling different kinds of mental disorder. I think that kinds should be individuated on the basis of causal mechanisms. I think there is a back and forth process between postulated kinds and discovery of causal mechanisms (which leads to a revision in the kinds that have been postulated) which leads to the discovery of causal mechanisms etc. We gain greater generalisability and predictive leverage with advances.

Are some of the above levels more fundamental than others? It is important to distinguish two different ways the question can be put:
1) Ontologically are some of the levels more fundamental than others?
2) With respect to explanation (answering questions) are some of the levels more fundamental than others?

With respect to the second maybe it depends on your question / what you want explained... E.g., do you think there is or could be a genetic explanation of why there has been an increase in the rates of anorexia or dissociative identity disorder in recent years? How about neurological? Is this because we haven't learned enough about genetics or neurology yet, or is there an 'in principle' reason why neurology and genetics aren't relevant with respect to that particular question?

I guess this makes me an anti-reductionist: Which level of fundamental depends on the question. Of course with respect to the structure of the world psychology depends on neurology but that doesn't mean that neurology is particularly relevant to answering psychological questions. By analogy if I get a program error in Word I'm not sure how digging around in the hardware is likely to help.

Its relevance has to be established before its priority.

With reductionism there is also the worry of 'why stop there'? why stop at neurology or genetics? Surely chemistry is more fundamental. But then surely physics is more fundamental than that.

Mind (consciousness) is reducible to psychology
Psychology is reducable to biology
biology is reducible to chemistry
chemistry is reducible to physics
but physics requires an observer (arguably)
which brings us back to mind.

(I'm sorry I can't remember where I picked that up from but I am fairly sure I didn't make it up myself).

I guess that is a song (not at all an argument) against one level being ontologically fundamental even...

There isn't very much analytic philosophy of psychiatry out there though there is a long tradition of continental philosophy of psychoanalysis and social constructivism and the like.

http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=10687

The above has been credited as being the first book length treatment of psychiatry by an analytic philosopher. Depends on what you mean by an analytic philosopher, I guess, but this guy is uncontroversially so. The following journal has some really good stuff in it. Though you might have to dig...

http://www.press.jhu.edu/journals/philosophy_psychiatry_and_psychology/

 

[toby jones]

I'm sorry most of that probably wasn't very clear.

I guess my take is that all of those levels are important to understanding what the psychiatric kinds actually are. There are causal mechanisms at each level that contribute to the production of the behaviours.

It doesn't really matter which field you choose to work in because there is important work to be done in all of them.

I suppose I was trying to get you to rethink your reductionism.

 

[solumanculver]

I'm sorry most of that probably wasn't very clear.

I guess my take is that all of those levels are important to understanding what the psychiatric kinds actually are. There are causal mechanisms at each level that contribute to the production of the behaviours.

It doesn't really matter which field you choose to work in because there is important work to be done in all of them.

I suppose I was trying to get you to rethink your reductionism.

Hi, I'm not quite sure what you mean by anti-reductionism... My impression is that psychological states are reducible to brain states, which is pretty much standard functionalist fare. It's also my impression that the only alternative to psychological/neurological supervenience is interactionist dualism. Do you agree with that?

It seems like if there is a gap in reductive explanation between any two levels of mental functioning that necessitates an ontological gap as well, which is problematic for me in my conception of psychiatry, which is grounded in a physicalistic notion of mental illness.

I'm not sure if I'm reading your schedule of reductions properly, but it seems like you're saying that the psychological reduces to the physical, but plausibly the phenomenal is not reducible. I agree with this absolutely, but I don't think that it's relevant to psychiatry because I also take phenomenal consciousness to be epiphenomenal.

In any case, thanks for responding to my post. I'm not too interested in reading that continental psychoanalytic philosophy... I feel like I might as well read a James Joyce novel instead. Looking forward to seeing what you contribute to the field...

 

[toby jones]

Hey. Supervenience claims are typically thought to be weaker than reduction claims ('A supervenes on B' can be true while 'A reduces to B' is false).

It is typically accepted that psychological events (or states if you prefer) supervene on brain events. That is just to say that if there is a difference in psychological event then there must be a difference in brain events BUT it is perfectly consistent with the supervenience claim that a difference in brain events does not entail a difference in psychological events. (Neural plasticity and individual variation would be examples of how a the same psychological event can be multiply realised in neurology). Supervenience is thus a one-way, a-symmetric dependency relation.

Reductionism is a stronger claim of a logical two way dependence (or identity). It is worth distinguishing between two different varieties of reductionism (or identity): a type-type version and a token-token version. The token-token version is only slightly stronger than the supervenience claim. Again: To say that psychological events supervene on neurological events is simply to say that a difference in psychological evenst entails a difference in neurological events. The supervenience claim doesn't rule out the possibility that a computer (without neurological events) could be programmed to have psychological events. To say that psychological events are reducible to neurological events, however, would entail that something lacking neurological events could not have psychological events.

An even stronger claim (and I think this might have been the one you were thinking of) would be that types or kinds of psychological events can be reduced to types or kinds of neurological events. One way this could happen, for example, would be if pain turned out to be c-fibers firing. If there was a perfect correlation between pain and the firing of c-fibers then one could say 'pain just is nothing over and above the firing of c-fibers' which is to say that 'pain can be reduced to the firing of c-fibers'. The trouble here isn't just that the correlation is false, it is that there doesn't seem to be a one-one mapping of different kinds of psychological events with different kinds of neurological events. There doesn't seem to be a kind of neurological state that just is the psychological state of belief.

Functionalism is consistent with token-token identity or reduction but functionalism is not consistent with type-type identity or reduction because a feature of functionalism is that it allows for multiple realisability. Functionalism says that a type of psychological state (such as belief) will have some instantiation or other (whether it be neurones or immaterial mind-stuff) but that there is no kind-kind mapping between levels.

If you think that it is perfectly possible for a being without neurones to have psychological states (and it certainly seems possible in principle) then you might want to hold off the reduction claim. Token-token reduction might be true of this world but type-type seems to be false. Supervenience is probably a better bet because it is less commital. Thus we can say that psychology supervenes on biology supervenes on chemistry supervenes on physics without committing ourself to the notion that the entities, properties, events, and laws posited at one level can be reduced to entities, properties, events, and laws at the lower level. Especially... When we are interested in kinds or types.

I'm not meaning to deny supervenience just reduction.

Though with respect to supervenience...

If schizophrenia supervened on genetics then that would entail that a difference with respect to schizophrenia would entail a difference with respect to genetics. But there are identical twins who are genetically identical but differ with respect to whether they have schizophrenia or not. That seems to show the supervenience claim to be false...

Hmm.

> I'm not too interested in reading that continental psychoanalytic philosophy... I feel like I might as well read a James Joyce novel instead.

Right. Sorry I don't think think I was clearer. Both the links I provided are good. I re-read what I said and I'm sorry I wasn't clearer... The first link is a link to a book that just came out last year. It will be a foundational text for analytic philosophy of psychiatry. He claims it is the first text written on the subject from within analytic philosophy but I have read some others of a similar style that weren't actually written by analytic philosophers. More psychiatrists doing philosophy of science. The quality was a bit variable. That book is brilliant, however. Certainly something to think about.

The second link was to an interdisciplinary journal between philosophy, psychiatry, and psychology. There are some wonderfully analytic articles in there and there are some that are in more of a continental style too. If you dig around a little you should be able to figure it out on the basis of the title of the paper.

 

[toby jones]

Okay. I didn't think I'd need to do this but I do...

There are two different kinds of supervenience: Local and Global. In fact there might be more kinds but this distinction is really very relevant.

Mental state M supervenes on physical state P is a description of the global supervenience claim. Mental state M supervenes on neurological state N isolates the neurological states as the physical states that are relevant, howver. There are a variety of thought experiments involving twin earth and mental content that are supposed to show us that mental states globally supervene rather than locally supervene. It gets really technical and I'm giving myself a headache already.

I just wanted to say that while it is false that mental disorder supervenes on genetic state it could still be the case (we would expect it to be the case)that mental disorder supervenes on physical states. Environment. Nutrition and toxins and cerebral trauma and social interaction might well be physical states that are relevant. I just mean to say that genetics (and neurology) might be A cause of mental disorder but they are never going to be THE cause of mental disorder. Not even a single token instance of mental illness (forget about which category it is). But they are certainly causally relevant for some instances.

All this is really controversial. If I start editing I won't stop, however. One really could write a thesis on this stuff. I do think, however, that biologial redutionism is typically accepted to be false within current analytic philosophy of science people it is just psychiatrists and neurologists and neuropsychologists who seem surprisingly attached to the view...

 

[solumanculver]

Hey,
Thanks for the clarification. I realized that when I wrote reduction what I really meant was simple supervenience, although I'm still not clear on the difference between supervenience and token identity. It seems like the notion of supervenience leads us to say something like: every psychological state can be redescribed at a more fundamental level in terms of neuronal activity, the way that a dot matrix picture can be redescribed entirely in terms of dots. A token-token theory would have us say: this particular instantiated psychological state is identical to this particular pattern of neuronal activity... both seem to require that there is nothing above and beyond the pattern of dots on a fundamental level. Do you think that the difference is in the referent of psychological terms? Like if an instantiated psychological state is identical to a pattern of brain activity, when you make a proposition that involves that particular state it is equivalent to a proposition about the brain activity, whereas it might not be the case under a theory only involving psychological/neurological supervenience?

That business aside, I'm not quite sure what you mean about schizophrenia. you're right that it can't supervene on genetics because of the twins, but it certainly still supervenes on brain states. Say some experience in a person's life instantiates some pattern of neuronal firing, which turns on a broken gene, which sends out a broken protein, which makes them go crazy. Their mental illness is still entirely supervenient on their brain state, which also incorporates information about their relevant life experiences. It seems like the levels of explanation above the neural, like the psychological or behavioral or whatever, are important ways to diagnose the problem... you could keep going higher and look at the economic ramifications for society to extrapolate the effect of the disorder, but it seems like if you wanted to treat it you would have to treat the underlying brain disorder qua brain disorder.

Although, that being said, when you send a person to therapy and their behavior changes, that means that something about their brain must necessarily have changed, even though you didn't address the brain problem as a brain problem, but rather as a psychological/behavioral problem. But on a neural level you're activating certain neural pathways, causes certain genes to be turned on/off, and leading to a change in psychological state...

 

[toby jones]

Hey. Thanks for this discussion, I'm finding it really very interesting 🙂

I did wonder if you meant supervenience instead of reduction. I guess I have some background with reading about the bio-psycho-social vs bio-bio-bio debate and given your background I thought that it was possible that you really mean reduction. Oftentimes I'm not quite sure what I mean but the process of discussion helps clarify my meaning not only for others but also for myself. When I read through my post I found myself wondering what the difference between supervenience and token identity was too. I was tempted to edit to sort that out, but I worried that I might be digging myself a deeper hole. I'm not at all sure that I can sort that out satisfactorily.

Individuation of token states (or events) is problematic. If I experience pain then become distracted then experience pain again is that one token pain or two? Who knows... Leibniz law allows us to say that if token state M has a property that token state P lacks then M cannot be identical to P. What we say about token identities depends on properties that tokens have compared to the properties that types have. For example: Token physical state P has the property of being grey and squishy. Token mental state M does not have the property of being grey and squishy. Therefore, by Leibniz law... One could of course say that of course a token mental state does indeed have the property of being grey and squishy after all... Other kinds of properties that are thought to be relevant for defeaters of identity claims are modal properties. Mental state M is essentially subjective, Physical state P is essentially objective. Therefore by Leibniz law... I'm not sure that modal properties attach to token states / events or whether they attach to type states / events, however. So there are worries like those. But yeah, I guess I'm not really sure on the difference between supervenience and token identity. If you believe it is possible to have a phenomenal state in the absence of any physical state whatsoever then I think that is still consistence with supervenience but I don't think it it consistent with token identity, however. Similarly with if you treat phenomenal properties as brute entities that can't be reduced to lower level properties. But these examples are peculiar to conscious properties and if you aren't worried about consicous properties (as we aren't really) then it is hard to know what lessons to take from this. Well, I'm finding it hard to know what lessons to take.

One thing that I can say, however, is that science deals in types or kinds rather than in tokens. The twin aims of science are thought to be generalisation and prediction (where explanation is kind of very roughly a backwards prediction) and you don't get generalisations and predictions from dealing in tokens but you do get them from dealing in types. Of course figuring out what the types are is problematic (your original problem). One way we could get type-type identities is to revise the types on two levels so they are found to co-vary.

So you grant me that schizophrenia can't supervene (locally) on genetics. So now the issue is 'does schizophrenia supervene (locally) on neurology?' I'm not sure what to make of the relevance of the twin earth thought experiments that argue against local supervenience and leave us with gobal supervenience. One thing that is hard with philosophy is that philosophers often worry about the nature of things in general (ie essential properties or conditions across possible worlds) rather than the ACTUAL nature of things in the ACTUAL world. As scientists we are more interested in actualities than possibilities. Philosophers typically want to leave it open that a being without neurology could have cognition (thus don't want to identify cognition in general with neurology) but if you are interested in what makes it the case that people and animals actually can cognize then neurology does of course seem relevant. Similarly, it might be possible for a cognizing computer to have mental illness but we aren't really interested in that - are we? I find it semi-interesting but I'll leave that project to somebody else...

Yeah, it sounds plausible to me that mental illness supervenes on neurology. And it seems plausible to me that neurology supervenes on genes + environment. Teasing out what factors of the environment are relevant and the precise way they interact is hard. But still seems that neurology supervenes on genes + environment. Psychiatrists don't seem to talk much about cognitive psychology...

Seems like there is going to be some kind of looping model of how these things inter-relate. Supervenience is interesting because it is a one way a-symmetic relation. There is a lot of controversy over what supervenience actually is (is it a claim of logical priority? Metaphysical priority? Causal antecedence?). But it seems to be one way of making the relationship between levels more precise. Perhaps.

> if you wanted to treat it you would have to treat the underlying brain disorder qua brain disorder.

Well... I guess it is controversial whether mental disorders are behavioural symptoms or whether mental disorders are the mental causes of the behavioural symptoms. Either way I'll grant that the mental / behavioural disorder supervenes on neurology. So in order to change the disorder we know we need to change the neurology. There are many different ways of changing the neurology, however. If you want to teach somebody to cook you are going to have better luck altering their neurology by showing them how to cook than you are going to have luck with altering their neurology by surgery or placing electrodes in their skull. Similarly (for some disorders) if you want to change the behaviour / mental states sociological intervention (remove them from the warzone or tenement), psychological intervention (teach them how to meditate or whatever) etc etc all can work to change the neurology. We know they must work by changing the neurology (because of the supervenience) but supervenience doesn't entail anything at all about how we are best to intervene in order to change things...

Neurology seems to be more central than genetics but maybe that is because the genetic + environmental interaction is so poorly understood. I think it is cool that it is kind of like sociology getting in there right at the level of genes (sort of like how people worry about consciousness getting in there right at the level of physics).

 

[solumanculver]

Mental state M is essentially subjective, Physical state P is essentially objective. Therefore by Leibniz law... .

Hi, I think that mental state M is only subjective inasmuch as there is a phenomenal experience associated with it. If we abstract away the phenomenal element, as we both agree that it's not relevant to the practice of psychiatry, then a mental state modulo the associated experience can be said to have a token-token identity relationship with the informational state associated with a pattern of neuronal firing, where the informational state is defined purely in terms of causal/functional relationships and not properties like grayness and squishyness. That way you can define a state as mental when it's instantiated by a computer program regardless of the fact the there is (possibly) no phenomenal component to it and there is no sloppy gray stuff associated with it.

You know, it seems like property dualist programs like David Chalmers' are portrayed by some philosophers as being dangerous and antiscientific because they propose non-physical epiphenomenal mental properties, but I think that if we buy his arguments then it puts us in a better position to think about aspects of psychiatry. As long as phenomenal states are considered causally effective then we won't be able to abstract them from an account of the mental and bridge that subjective/objective gap that you were mentioning. If we divide the mental into two pieces Q1 and Q2, where Q2 is the phenomenal experience associated with Q1, then I think that leibniz law won't stand in our way of saying that there can be a token identity between informational states of the brain and Q1 states, which are roughly the functional components of a mental state. Despite what some philosophers say, like the Churchlands, I don't think that it's even conceivable in the limit of a perfected neuroscience that the subjective/objective gap can be filled in with more physical explanation, and for that reason I think that any program that can't abstract the phenomenal from the rest of the mental won't be able to explain the parts of the mental that are relevant to psychiatric illness.

So basically, I think that if you look at two brain states b1 and b2, where b1 causes b2 and you only consider the causally relevant components of b1 and b2, then I think that each of these causally relevant components can be redefined as a mental component with the exact same causal relevance to other mental components in the associated mental states m1 and m2, and you have a token-token identity theory of mind. The only thing that's left is the phenomenal experience that is associated with (at least) some informational states, but that is taken as brute, and is not relevant anyway.

by the way, I really appreciate this discussion as well. It seems like not many medical types care about this stuff....

 

[toby jones]

> I think that mental state M is only subjective inasmuch as there is a phenomenal experience associated with it…

Okay. I’m going to talk about properties instead of states (because a single state can have both informational and phenomenal properties and it might be that mental states are such states). People sometimes talk about psychological states (aka representational states aka informational states) as being functional states where to be in a certain psychological state is simply to be in a state that plays a certain functional (informational or representational or action guiding) role.

This makes no mention of phenomenal properties. It seems that it is the phenomenology that is subjective so yeah, I agree with you in that. It seems that so far as the science of the mind is concerned we can simply put phenomenal properties to one side (seeing as science deals in the objective rather than the subjective).

There might be a problem with this view, however. Searle argues that mental states only count as mental insofar as it is possible for them to be consciously experienced (the ‘Connection Principle’). He doesn’t mean to say that mental states are always consciously experienced (it is possible to have unconscious beliefs or to continue to believe the sun is hot without being phenomenally aware of this belief). He just thinks that belief is a mental process because we can be consciously aware of the mental state. And something only counts as a belief if it is possible for us to become consciously aware of it. Consider the mechanisms in our visual systems that allow us to detect edges, for example. The mechanisms that enable us to detect edges are pre-conscious, for example (in the cognitive psychological rather than psychodynamic sense) of their being a process that is sub-personal or below the threshold of conscious awareness (in principle). As such, Searle argues that edge detection is not a mental process. I’m not sure that I quite understand Searle… As such it is hard for me to know whether I agree or not… But this could be problematic.

In the same vein other theorists (Chalmers, for example) have argued that phenomenology is basic and informational processing, intentionality, or representational contents is derivative. As such one can’t put phenomenal properties to the side and continue to study cognitive psychological processes or neurological processes qua mental processes.

It is hard to know what to make of this. Really very. I think that there is important work to be done with respect to the phenomenology of mental illness (in the analytic philosophy tradition rather than in the continental tradition of the great phenomenologists) but… That is not my project. I’m not sure of how that would go. I suppose we need to have an account of how these things typically work in order for us to derive an account of how things are going wrong in various abnormal phenomenal experiences. That doesn’t seem to be a scientific project, however. Maybe insofar as a science of psychopathology is concerned we can just leave this to one side. We might be ignoring relevant data, however, as phenomenology or subjectivity does indeed seem to be something that occurs in the natural world.

It sounds like you are attracted to functionalism. That is typically considered to be the level of cognitive psychology (where they talk about information processing). There is a lot of debate about the relationship between cognitive psychology and neuropsychology. Sometimes cognitive psychologists say that neuropsychology is irrelevant with respect to cognitive modules because cognitive modules don’t have to be localised. For example, a cognitive theory of autism is that there is a breakdown in the Theory of Mind module (TOM). They don’t worry about whether this module is a neurophysiological module at all. The Shared Attention Mechanism (SAM) is thought to be a mechanism in the TOM. The SAM might have better prospects for localisation but some cognitive psychologists say that neurology has nothing to do with it.

If you are trying to come up with an account of the functional structure (modules with causal roles) of the program Word on the basis of double dissociations (the kinds of tasks that come apart when you damage the system) then hardware is simply irrelevant. Neuropsychology cannot decide between two competing cognitive theories and localisation (and hence neuro-imaging) is irrelevant for cognitive psychology. I would say: So much the worse for cognitive psychology. It can isolate itself from the rest of the sciences of the mind by declaring certain data to be irrelevant but sounds like a degenerative research program to me. Cognitive neuro-psychology (which engages in a top-down and bottom-up approach to find structure / function mappings) sounds like a far better (and more integrative) discipline. Seems to me that if you are interested in the way people actually do things (the actual causal processes going on inside people) then both hardware (neurological) and software (cognitive) descriptions are relevant and clearly there is a supervenience relationship at least… And yes token identity though token identity is really very cheap and not relevant for science insofar as token identity doesn’t support generalisation and prediction.

People might disagree with Chalmers, but I don’t think that anybody thinks he is a crank anymore. The notion is that currently in physical theory there are properties that are taken as brute or basic such as mass and spin and charge. He thinks phenomenal properties are on a par with current basic physical properties such as these. Given the current state of science phenomenal properties are irreducible to currently endorsed basic physical properties (such as mass and spin and charge). He allows that physics could progress in such a way that the properties that are currently taken as basic can be reduced / explained / shown to supervene on properties that are more basic. It is possible that those more basic properties are proto-phenomenal in the sense that they are neutral with respect to mental / physical and that their interaction can predict both the physical and phenomenal properties of our world. So he isn’t anti-physics. It has become fashionable for people to ask ‘what is physicalism anyway? The properties endorsed by current physicists or the properties endorsed by the final physics?’ I think that Chalmers point is that final physics will have phenomenal properties in it but that current physics has an ontological gap (dualist divide) between phenomenal properties and physical properties. So much the worse for current physics. (Just my understanding of him).

 

[Vader]

Wow--this is quite a discussion!

 

[solumanculver]

>
There might be a problem with this view, however. Searle argues that mental states only count as mental insofar as it is possible for them to be consciously experienced (the ‘Connection Principle’). He doesn’t mean to say that mental states are always consciously experienced (it is possible to have unconscious beliefs or to continue to believe the sun is hot without being phenomenally aware of this belief). He just thinks that belief is a mental process because we can be consciously aware of the mental state. And something only counts as a belief if it is possible for us to become consciously aware of it. Consider the mechanisms in our visual systems that allow us to detect edges, for example. The mechanisms that enable us to detect edges are pre-conscious, for example (in the cognitive psychological rather than psychodynamic sense) of their being a process that is sub-personal or below the threshold of conscious awareness (in principle). As such, Searle argues that edge detection is not a mental process. I’m not sure that I quite understand Searle… As such it is hard for me to know whether I agree or not… But this could be problematic.

Hi, I think that Searle's idea of the mental, though valid, might not have the greatest utility. I think that the class of mental events that can be consciously experienced is a very important set of data for us to make generalizations about the mind, but I think that limiting the mental to this set might unnecessarily obscure the meaning of the term. Like I mentioned before, I think that unless you believe like the churchlands that a completed physicalistic neuroscience will be able to bridge the subjective/objective gap, then any account of the mental that specifically requires the presence of phenomenal experience seems like an account beyond the reach of science. Not to be too pedantic here, but whether or not a person/computer has phenomenal experiences is still not knowable data.

Searle, in general doesn't discuss this kind of problem very well... he always says something like "We all know that consciousness is a brain process, and we can infer that other people are conscious from our own experiences", but this has always struck me as something of an argument from ignorance. We can't know that anything apart from ourselves is conscious, so (searle says) we arbitrarily invent a kind of continuum by which anything with a brain is assigned a level of consciousness proportional to their degree of similarity to us, as we judge it. I think that this kind of vague idea of what objects have phenomenal properties is too weak to ground a definition of the mental... at least not how I think of the mental.

So according to searle no one in the zombie world (if it exists) has any mental properties at all? Even though they're saying and doing exactly the same things that we're saying and doing? I expect that he doesn't believe that zombies are possible, but I think even if they are conceivable but not possible, it seems intuitive that they still have some mental properties... After all, they themselves claim to have them.

>
Maybe insofar as a science of psychopathology is concerned we can just leave this to one side. We might be ignoring relevant data, however, as phenomenology or subjectivity does indeed seem to be something that occurs in the natural world.

It seems to me that actual phenomenal properties can't play any role on psychopathology. Certainly people with psychopathological states will experience abnormal phenomenal states, because phenomenal properties supervene naturally on (at least some) brain states. But in this case the essential problem is still in the brain, the phenomenal component of the problem is a kind of a free ride. On the other hand if you could imagine a person with some kind of phenomenal abnormality, like that they experienced colors the way we experienced sounds and vice versa, but didn't have a corresponding functional abnormality, not only would he be untreatable, but he wouldn't even know that anything was different about him... as a matter of fact, I might have this problem myself. Of course, this view presuppose epiphenomenalism, which has it's own problems, I guess.

 

[toby jones]

hey. yeah i get a bit of a headache when i think about phenomenology too much. i think i can fairly safely not worry about it. while there is a 'phenomenological tradition' of the study of mental disorder they don't mean quite the same thing by that as the philosophers do. i guess they are really talking about verbal reports of inner states.

what is the basic unit of research analysis? i've been thinking about that. the DSM takes the basic unit to be diagnostic categories. but there can be more variation in symptoms between individuals of the same diagnostic category than between individuals of different diagnostic categories. would it be better to take individual symptoms as the basic unit? some of the work on delusions has done that. delusions that arise from acquired cerebral injury seem to be interestingly different from delusions that arise within the context of psychosis (e.g., with respect to monothematicity, degree of circumscription etc). it might be that there are different causal mechanisms involved in the production of the Capgras delusion depending on context. So even symptoms might not form natural kinds with a common explanation.

Looking at prevalence rates of diagnostic categories (or symptoms) across the population kind of assumes that there is something interestingly similar about those individuals. i think it is possible that the only interesting similarities might be with respect to their behaviour / verbal behaviour. i guess the medical model assumes that mental disorder is caused by breakdown / malfunction in some system (the brain). murphy says that that assumption does for psychiatry what adaptationism does for evolutionary biology, however. that is to say that sometimes the assumption is false and othertimes we don't know whether it is true or false but you have to start somewhere... i'm not sure what i think...

i'm thinking it might have to come back to the behaviour. in the beginning was the exemplar / prototype. the people who were uncontroversially behaving in such a way that people felt they needed to be locked up to protect them / society. hard to say much more about that. but i guess we wanted to find out what was up with them and people like them. and over time we consider more people to be like them (we allow that you don't have to be all that severe to count as being mentally ill). but a-priori it seems perfectly possible that these people aren't malfunctioning at all. that there is nothing malfunctioning about their inner mechanisms. you don't need a broken brain to get that kind of output. maybe they simply don't have anything interesting in common with respect to inner causal mechanisms. there would seem to be an indefinate number of ways that a computer could break down. i don't know. having some sympathy for a dimensional rather than categorical approach. having some sympathy for the notion that if the environment is stressful / traumatic enough... i don't know. i do get a headache sometimes ;-)

 

[Vader]

I also tend to think that pondering phenomenology, although intriguing, is at this point is not a very effective means of producing treatments for psychiatric disorders.

From the standpoint of psychiatric disorders, identifying the neural systems affected by the disorder and the genetic bases seems the logical first step. One of the more successful approaches has been to examine relationships between endophenotypes of disorders (i.e. working memory deficits, prefrontal cortex dysfunction) and genetic polymorphisms, the idea being of course that components of the syndrome may be more amenable to genetic and neuroimaging analyses.

A major thrust is to identify which neural systems are affected in psychiatric disorders, examine the genetic and molecular basis for the function/dysfunction of these circuits, and therefore identify possible drug or psychotherapeutic targets that could hone in on and modify activity of the key neural circuitry.

Personally, I am very excited by the fact that psychiatry as a field is moving toward a more biological focus and will in the future have even better treatments, while also producing new knowledge of the neural basis of mental function.

 

[toby jones]

> One of the more successful approaches has been to examine relationships between endophenotypes of disorders (i.e. working memory deficits, prefrontal cortex dysfunction) and genetic polymorphisms, the idea being of course that components of the syndrome may be more amenable to genetic and neuroimaging analyses.

That is very interesting to me. Is there a back and forth process with respect to identifying the endophenotypes and the genetic polymorphisms? I've looked at the relationship between cognitive psychology and neuropsychology with respect to identifying cognitive modules and neurophysiological structures and (arguably) there seems to be a back and forth process. I'm wondering if the same thing applies here. Um... Is an 'endophenotype' a small unit of behaviour or a cognitive ability or something like that and a 'genetic polymorphism' the genetic basis for that endophenotype? If you can think of something I could read on this (preferably an article) I'd be grateful.

Does anybody know how one breaks up 'environmental influences' on gene expression. I know you can look at specific things like 'influenza virus exposure' but things like 'immigration' and 'trauma' must be a bit harder to manipulate in the lab. I find this really interesting but am concerned about people like Kandel who think that psychiatry needs to move towards a more biological focus. There don't seem to be robust explanations available to us at the genetic level for psychiatric conditions (e.g., concordance rates for schizophrenia in identical twins only 48%) unlike such conditions as Huntington's... But maybe endophenotypes are more robust?

 

[Vader]

That is very interesting to me. Is there a back and forth process with respect to identifying the endophenotypes and the genetic polymorphisms? I've looked at the relationship between cognitive psychology and neuropsychology with respect to identifying cognitive modules and neurophysiological structures and (arguably) there seems to be a back and forth process. I'm wondering if the same thing applies here. Um... Is an 'endophenotype' a small unit of behaviour or a cognitive ability or something like that and a 'genetic polymorphism' the genetic basis for that endophenotype? If you can think of something I could read on this (preferably an article) I'd be grateful.

Does anybody know how one breaks up 'environmental influences' on gene expression. I know you can look at specific things like 'influenza virus exposure' but things like 'immigration' and 'trauma' must be a bit harder to manipulate in the lab. I find this really interesting but am concerned about people like Kandel who think that psychiatry needs to move towards a more biological focus. There don't seem to be robust explanations available to us at the genetic level for psychiatric conditions (e.g., concordance rates for schizophrenia in identical twins only 48%) unlike such conditions as Huntington's... But maybe endophenotypes are more robust?

Here is an article on the endophenotype concept:
Gottesman et al. Am J Psychiatry 160:636-645, April 2003
http://ajp.psychiatryonline.org/cgi/content/full/160/4/636

This concept has allowed the production of animal models of certain aspects of complex neuropsychiatric disorders such as schizophrenia. Clearly, a mouse will not fully recapitulate the full clinical syndrome, but can still be useful for studying the genetic and neurobiological mechanisms of particular endophenotypes.

As for the second part of your post, there is clearly a large environmental component to neuropsychiatric disorders. Identifying the genetic factors that contribute to disease susceptibility allows for more thorough and higher-level analyses of gene-environment interactions. There is increasing evidence that variations in specific genes in combination with environmental factors confer increased susceptibility to drug abuse, schizophrenia and other disorders. Just read a review on this, but can't seem to find it... if I do I'll post the reference.

 

[solumanculver]

Hi,

Back to the original point of this this thread... I've decided to forgo the PhD for the MPH. Maybe I'm just not cut out to be a research scientist. I think that the question of natural kinds of mental illness is more interesting and more epidemiological in nature.

"There is increasing evidence that variations in specific genes in combination with environmental factors confer increased susceptibility to drug abuse, schizophrenia and other disorders."

I believe in this completely, but doesn't it seem like when you include genes and environment you've included everything? What other possible variable is there? I guess that the only other conceivable variables require reference to phenomenal consciousness or agent causation or something... one of which seems epiphenomenal by definition while the other requires non-causal closure of the physical world, I think.

"I know you can look at specific things like 'influenza virus exposure' but things like 'immigration' and 'trauma' must be a bit harder to manipulate in the lab."

yeah... it seems like mental illness, inasmuch as it is a biological phenomenon at the lowest level of explanation, must depend on gene expression and broken proteins or something. So it seems like if mental illness requires a genetic disposition and an environmental stressor, we only need to look at environmental conditions that differ from each other in terms of their effect on gene expression. It doesn't seem like any particular kind of stress is required to become schizophrenic, does it? Just the wrong genes and the wrong stimulus at the wrong time and shazaam - you got it. It must have something to do with whatever stuff goes on in a persons brain when they're in their late teens/early twenties, there's a window that if the wrong gene is turned on the whole thing collapses like a house of cards...