Evolution of Depression

[Soapy Sam]

What could be the evolutionary advantage of being able to suffer from depression? I mean why would an organism feel a sense of loss or defeat to the extent that their normal behavioural functioning is impeded?

No reason why I'm pondering this. I feel great. But it just struck me today after considering past experiences with severe depression that I couldn't think of a reason why we could suffer from it.

Athon

(my emphasis).

I tend to think this is one of Gould's "spandrels"- a feature which is a by-product of something else and which is neither actively selected for, nor against. We have brains. We have the ability to form close, long term bonds. In part the bonds are formed because brain chemistry rewards us for forming such bonds. If the bond is broken , there are neurochemical changes which can affect behaviour. Other stress may have similar result.

That's common I think, to many animals. I've seen a carrion crow literally starve to death after its mate was hit by a car. It just - gave up. It ain't just humans. In humans, conscious introspection makes it worse, like picking at a scab.

 

[articulett]

So to separate out human activities as interfering with evolution while ignoring the fact all organisms could potentially adapt to changes without genetic adjustments is really a false dichotomy. Humans are just able to adapt to differing environments to a greater degree than other species. Rats come a close second.

Being able to use science to adapt to differing environments is an evolutionary change in itself. While a diabetic may survive today, for example, they do so because of genetic advances in intelligence.

Well said, though I think roaches trump rats and humans in the adaption department.

 

[athon]

I don't read any substantial disagreements in your post that followed this one so I'm not clear on your specific objections. Perhaps you could simplify just the objections if I don't cover them below.

Hm, maybe it was either just the phrasing of it, or my poor reading. I think you covered the misunderstandings nicely in your follow-up, though. My apologies.

As far as non-social animals suffering emotionally, how would we know? Is a hibernating bear sad? How do you measure that?

I agree. We can only do our best to make certain comparisons in the expressed behaviour of an animal as it resembles that in humans. Of course, there is a great danger in doing this.

Athon

 

[athon]

(my emphasis).

I tend to think this is one of Gould's "spandrels"- a feature which is a by-product of something else and which is neither actively selected for, nor against. We have brains. We have the ability to form close, long term bonds. In part the bonds are formed because brain chemistry rewards us for forming such bonds. If the bond is broken , there are neurochemical changes which can affect behaviour. Other stress may have similar result.

That's common I think, to many animals. I've seen a carrion crow literally starve to death after its mate was hit by a car. It just - gave up. It ain't just humans. In humans, conscious introspection makes it worse, like picking at a scab.

That was one of my initial assumptions, but I couldn't help thinking that it really does have a rather negative influence on our state of being. Most spandrels, as it were, are relatively neutral, hence exist because they are simply carried along without either impeding or assisting the fitness of the individual.

Imagine an organism which is less likely to be depressed. Its mate dies, it suffers little depression and finds another mate. It can now pass on genes where the others will not.

I do realise I am oversimplifying slightly, and am happy to concede it might be purely an artefact of our neural chemistry... but for some reason I'm just not convinced.

Interesting about the crow, though. I didn't consider birds but now that I do, I can think of several other similar examples such as a number of Australian parrots (such as the cockatoo).

Athon

 

[Melendwyr]

The idea of using anti-depressants for pain is not based on the drugs alleviating pain directly. Rather some people complain of chronic problems with few or no physical findings like fibromyalgia. Anti-depressants help, suggesting the disorder is a psychiatric rather than a physical problem.

And yet the efficacy of antidepressants for depression is cited as a demonstration that depression is a physical problem.

By all means, let us not draw attention to the fact that cognitive-behavioral therapies are just as effective.

 

[ChristineR]

Not to get involved in your discussion here since I haven't followed it, but I had a comment on this.

The idea of using anti-depressants for pain is not based on the drugs alleviating pain directly. Rather some people complain of chronic problems with few or no physical findings like fibromyalgia. Anti-depressants help, suggesting the disorder is a psychiatric rather than a physical problem.

If anyone wants to attack that premise please don't hijack the thread as it is a different subject.

That's basically what I was trying to say, but I would emphasize that the pain is not a "psychiatric" problem but a problem with brain function. Fibromyalgia, for example, appears to be an abnormality in the normal muscle pain functions--nothing's being pinched, but something is acting as if it were.

 

[writerdd]

That's basically what I was trying to say, but I would emphasize that the pain is not a "psychiatric" problem but a problem with brain function. Fibromyalgia, for example, appears to be an abnormality in the normal muscle pain functions--nothing's being pinched, but something is acting as if it were.

That's an interesting idea. A lot of people view the brain as hardware and the "mind" as software and therefore psychological disorders fall under the software bug metaphor. However, it is more likely (in my opinion) that they are hardware failures. I'm not sold on the idea that there is a brain/mind or hardware/software duality in humans. I don't know enough about the way the brain works to have a good idea about this (and I'm not sure even scientists working in related fields know enough yet).

 

[Chris Haynes]

...The idea of using anti-depressants for pain is not based on the drugs alleviating pain directly. Rather some people complain of chronic problems with few or no physical findings like fibromyalgia. Anti-depressants help, suggesting the disorder is a psychiatric rather than a physical problem.

If anyone wants to attack that premise please don't hijack the thread as it is a different subject.

There is a pretty good explanation in the book All in My Head , including the description of how the first time it was tried did not work, but that the second time on a very low dosage worked. Only to become worthless after something falling and hitting her head. I cannot remember the details (library book), but this is a pretty good read with all sorts of theories and treatments being discussed.

 

[aggle-rithm]

That's an interesting idea. A lot of people view the brain as hardware and the "mind" as software and therefore psychological disorders fall under the software bug metaphor. However, it is more likely (in my opinion) that they are hardware failures. I'm not sold on the idea that there is a brain/mind or hardware/software duality in humans. I don't know enough about the way the brain works to have a good idea about this (and I'm not sure even scientists working in related fields know enough yet).

I used to use the brain=hardware, mind=software analogy, but it's not very apt. If the software were an emergent property of the hardware, and if it could somehow affect changes to the hardware itself, it would be a better analogy.

It would also be totally cool!

 

[Skeptic Ginger]

And yet the efficacy of antidepressants for depression is cited as a demonstration that depression is a physical problem.

By all means, let us not draw attention to the fact that cognitive-behavioral therapies are just as effective.

There is no question depression is physical. Didn't you go on about this on another thread? It's all physical. There is no such thing as something in our minds that does not have a physical component. There is no evidence for a "soul" separate from your brain. Psychological impacts on one's thinking still involves brain structure.

Anyway, getting back to the pain depression thing. Yes there is a physical event in both but blocking the pain receptor path is not the same as correcting the cause of pathological depression which is what the original post was about. It wasn't about whether or not something was "physical".

 

[Skeptic Ginger]

That's basically what I was trying to say, but I would emphasize that the pain is not a "psychiatric" problem but a problem with brain function. Fibromyalgia, for example, appears to be an abnormality in the normal muscle pain functions--nothing's being pinched, but something is acting as if it were.

I knew I wasn't going to get away with this example without some kind of response. So hopefully I'll just make one point and get back to the thread topic.

Do you have any minor discomforts that you just ignore? Of course. So there are two possibilities for psychogenic pain. One is an actual pain receptor pathway stimulant, whether originating in the nerve end or anywhere else along the path including the interpretive center in the brain. The other possibility is that one is paying more attention to the impulses along that pain receptor pathway which occur in everyone but which are usually ignored. It may seem like a nit pick of a distinction, and it may seem like it doesn't matter because the result is the same, real pain to the person experiencing it, but it does actually have very important implications in investigating and treating diseases like fibromyalgia.

Depression can be manifest in a multitude of ways not often recognized as depression. Not every person suffering depression mopes or feels sadness. Some people express depression with hostility and annoyance toward everything and some in perceived physical pain. Still others, not necessarily depressed (but it can be a co-diagnosis) report pain as a manipulative behavior where actual pain does not exist and perceived pain is not necessarily something triggering the pain pathway. We typically think of such behavior as drug seeking and some is, but not all.

Denial is part of the cascade of events so should be mentioned as well. Again addiction is a typical problem in which denial plays a big part, but there are other reasons one uses denial as a protective mechanism. And keep in mind that not all people using pain as a drug seeking behavior are outright faking the pain. It is an unconscious behavior in many cases.

Take a depressed person who's job is being affected and is affecting them in that they are having performance problems. They cannot get motivated to work. Their boss is giving them bad performance evaluations. But the depressed person doesn't recognize the depression is the underlying cause. The depressed person doesn't allow the performance evaluations to be considered because there is an ego protecting mechanism manifesting itself as denial. However, if one is experiencing pain, now that person can rationalize they have a "legitimate" reason to not go to work and to be performing poorly.

Pain with no cause outside of the brain isn't always drug seeking behavior, it isn't always depression, sometimes it's just how that person learned to cope with any number of things. Have you ever felt so overworked that getting sick sounded good because you could rest and do nothing?

Pain can be a symptom, a depressed person can be more sensitive to normal stimuli. Pain can be a protective mechanism, a person in denial for whatever reason has pain which legitimizes something else. And, pain can be manipulative behavior, drug seeking for example but there are other rewards such as attention or relief from responsibility. You can see that things get very complicated. Diagnoses are hard to make because the reasons for one's brain to use pain as a protective or coping mechanism are not always obvious.

Now, with all that said, and I do think with fibromyalgia the studies have been extensive enough, every once in a while a new disease is discovered that wasn't recognized that people do have that has nothing to do with psychological or behavioral factors yet was believed to be psychological. The key in the case of fibromyalgia is the almost complete failure of pain medications to treat the symptoms, and the fact that of all treatments, antidepressants are just about the only thing that has resulted in improvement in any patients.

OK, I'm too far off topic now but hopefully discussing the fact that depression is manifest in different ways was useful.

 

[Melendwyr]

There is no question depression is physical. Didn't you go on about this on another thread? It's all physical.

Do not conflate philosophy with physiology. Depression and other mental illnesses are not known to be physiological disorders.

 

[Skeptic Ginger]

That's an interesting idea. A lot of people view the brain as hardware and the "mind" as software and therefore psychological disorders fall under the software bug metaphor. However, it is more likely (in my opinion) that they are hardware failures. I'm not sold on the idea that there is a brain/mind or hardware/software duality in humans. I don't know enough about the way the brain works to have a good idea about this (and I'm not sure even scientists working in related fields know enough yet).

There are structural, chemical and electrical components of the brain. You could use the software metaphor to describe programming behavioral components, in other words the environment or "nurture" as the term is often used. And the operating system might be a metaphor for the way in which the brain stores and organizes data. We are hardwired to categorize data for example. Once you learn what a tree or a face is, you know a new tree or new face without having to learn specifically what the new thing is. Somewhere whether early learning or hardwire, we expect light to be coming from above. So when we see a picture of a crater with the shadow upside down it looks like a hill, and so on.

But we also know some learning experiences are tied to the physical brain structure. If you don't learn language by a certain age, you cannot learn it. Without a particular bonding experience as an infant, severe behavioral problems occur later which are unavoidable. These kind of psychological problems are not currently treatable with drugs or surgery. Whether in the distant future however we might be able to correct whatever part of the brain is abnormal is unknown. Somewhere in those brains lies the physical component of that behavior.

 

[Skeptic Ginger]

There is a pretty good explanation in the book All in My Head , including the description of how the first time it was tried did not work, but that the second time on a very low dosage worked. Only to become worthless after something falling and hitting her head. I cannot remember the details (library book), but this is a pretty good read with all sorts of theories and treatments being discussed.

Keep in mind not all fibromyalgia need have the same underlying cause as I noted in my above post. Afterall, the diagnosis is all subjective.

 

[Skeptic Ginger]

Do not conflate philosophy with physiology. Depression and other mental illnesses are not known to be physiological disorders.

Melen, you went on about this before and provided absolutely no evidence to back up your personal explanation for depression. It is your own magical, without any basis, view of the brain.

Apparently in multiple threads.

http://www.internationalskeptics.com/forums/showthread.php?t=54887&page=4
http://www.internationalskeptics.com/forums/showthread.php?p=1373336#post1373336

Nuff said.

 

[Melendwyr]

I have no personal explanation for depression. Nor have I presented any explanation, personal or otherwise.

All information-processing systems are physical by definition. That does not mean that it is impossible to distinguish between their hardware and their software; one emulates the other, and software can go wrong without their being any problems whatsoever with the hardware.

Our brains' function is to respond to incoming information with highly complex behaviors. It is far, far easier to define pathological states for our other organ systems than it is for our nervous systems for that very reason.

Ignoring the implications this may have on their functioning is not only absurd but dangerous to the cause of knowledge, not to mention medicine.

Psychiatric conditions that have physiological etiologies that become known are moved away from psychiatry and into neurology: pellagra, neurosyphilus, and epilepsy are just a few of the examples. Conditions are considered psychiatric because they have no known medical cause.

 

[writerdd]

There is no question depression is physical. Didn't you go on about this on another thread? It's all physical. There is no such thing as something in our minds that does not have a physical component. There is no evidence for a "soul" separate from your brain. Psychological impacts on one's thinking still involves brain structure.

Anyway, getting back to the pain depression thing. Yes there is a physical event in both but blocking the pain receptor path is not the same as correcting the cause of pathological depression which is what the original post was about. It wasn't about whether or not something was "physical".

Still, I think there is something to the idea that the mind, whatever that means, does have some sort of feedback loop where mental processes feed on themselves. Well, I didn't explain that very well, I don't think.

A simple example is that if you get depressed and you keep reading bad news and talking to yourself about negative things, you keep getting more and more depressed. (Not to over simplify, the endocrine and immunological systems also have a part to play in long-term depression.) Sometimes (not always) you can break this negative feedback loop by forcing yourself to focus on positive things.

If you get carried away with this, you fall into pop psychology ideas that probably have no solidity. But there is some truth to the general idea. Just as the way physics was distorted in "What the Bleep," some real neurological and psychological phenomena get distorted in various self-help books.

On the other hand, there are some very good scientific books on the same subjects. (Alas, probably with a much smaller audience.) Antonio Damasio, for example, talks about these ideas in his books "The Feeling of What Is" and "Looking for Spinoza."

Both are worth reading if you're really interested in the topic of the operation and evolution of emotions.

 

[Chris Haynes]

Keep in mind not all fibromyalgia need have the same underlying cause as I noted in my above post. Afterall, the diagnosis is all subjective.

The referenced book is about chronic migraine, not fibromyalgia. Sorry for the confusion. Though the comment about not having the same underlying cause is still valid.

I ony mentioned it because the author was helped for a while with Prozac. (I also know someone who has had chronic migraines for decades, which seemed to lead to depression, and finally to a psychotic event that caused her to spend time in Harborview's psych ward where she got a diagnosis of bipolar. Got medication, some talk therapy and seemed to be doing well. After being released with NO further support she went back to using homeopathy... and declined again... ugh).

 

[Chris Haynes]

I have no personal explanation for depression. Nor have I presented any explanation, personal or otherwise.

....

We noticed that. You have also not provided any reason for us to believe you nor take you seriously.

 

[Skeptic Ginger]

Still, I think there is something to the idea that the mind, whatever that means, does have some sort of feedback loop where mental processes feed on themselves. Well, I didn't explain that very well, I don't think......

My post on antidepressants as pain medications started with

Depressed people are often overwhelmed, oversensitive and very reactive to pain, I don't suppose that you are aware of the use of ADs to treat pain, are you?

who was responding to something ChristineR had said to him. To that I replied that the treatment was not specifically aimed at blocking the pain receptor pathway. I didn't say anything about the antidepressants not being useful in some patients who were experiencing pain.