What are the exact medical causes for clinical depression?

Factual Questions
1

My Philosophy professor refuses to believe me when I tell him how clinical depression affects people. This was brought up when we were talking about “brain” v “mind”, and I pointed out that chemicals cause emotions. As proof of this, I pointed out that people with severe clinical depression often do not feel anything (barring a deep sense of despair or hopelessness), including love, because of chemical imbalances. And that while therapy helps people deal with the effects of the depression, it doesn’t really cure the cause (chemical imbalances).
He insists that “human beings will never stop feeling.”
I think this is bull.
Now, I could use my own personal example, but that’s not very scientific, so I thought I’d gather more information. Especially since I’m not a doctor, I’m just a college freshman, so what do I know?

Also, he wants to know why clinical depression is not “universal”, if it’s “really” a malfunction of the brain. After I picked my jaw up off of the floor, I pointed out that he is more likely than I to develop Sickle Cell Anema, (he’s black) that doesn’t mean the disease does not exist.
I don’t know if clinical depresion is Universal…but seeing as how the disease is hereditary, it stands to reason that certain cultures are more susceptible to it than others. For example, if one person 400 years ago developed Clinical Depression, and it didn’t kill him, and he went on to have 10 children, all of which have it, and they each went on to have 10 children (all of which have it), and all of them move to The New World, and it just continued like it would only take a few hundred years before a sizable portion of the population is affected. But anyway, that’s just speculation, as I really don’t know anythig for sure.

2

Hmm. Depression might be a positive factor for reproduction. After all, if one’s feeling upset…

But saying chemicals cause emotions is like saying “electrons cause emotions”. Big so what. Either there’s a physical manifestation for something, or there isn’t, and it’s supernatural.

That mental disorders can be “treated” with chemicals doesn’t prove we understand the disorder. Pick some problem you know very well, say, not getting wet in the rain. How many different ways can you think of to avoid getting wet? It doesn’t mean you understand how it rains, why people get cold, etc.

Your professor’s comment about universality sounds odd. I’m trying to guess what he meant. It’s reminiscent of a rebuttal to an argument the Russians put forward decades ago that all human emotions are chemical. It was pretty radical and annoying to the West at the time. Upset us so much Hollywood made a musical about it with Fred Astaire and Cyd Charisse.

Needless to say, love won out. A philosophically satisfying movie.

3

The only reason we were discussing it is because we were discussing how the mind developed. (It is a philosophy class, after all).
His stance? God did it. God programmed us a certain way and gave us our consciousness, therefore, the biological functions of our brains are irrelevent.
We’re also reading Why God Won’t Go Away, which outlines what happens to the brain during an intensely religious experience. He resents the implications that our brains have anything to do with 'mystical experiences". I’m confused on how he thinks we can experience anything at all, if we don’t use our brain?
That’s either here nor there though, I’m just giving context.

My point is this. Clinical Depression is clinical depression becaues people are, well depressed. Not happy. I’m asking, is this caused by a chemical imbalance? I’m assuming it is since it’s treated by medication.

4

The “God did it argument” is worth about a sneeze, regardless of one’s religious inclinations. Granted.

I haven’t read “Why God Won’t Go Away”, but honestly, I doubt I need to. If you believe in God, then you accept that at some point, in some way, our existance is affected by God. But maintaining that his influence occurs in some predicatable way is contrary to what Christ said. Not to go all religious on you, but when Christ was asked to jump off a roof to prove God was with him, he answered “You cannot put God to a test.” This was an important statement, and one which your professor is apparently ignoring. Your prof’s trying to say that God/Jesus is responsible for some particular thing that he, personally, would like proved true. It’s not either a legitimate religous or scientific argument.

I have an issue with “clinical depression”. My mother’s a shrink, and my sister’s a doc, and they both take drugs to treat their depression. I refuse. I don’t know or care whether they think I’m clinically depressed. Just because I don’t have a perfect physique (although it’s pretty good, heh, heh) and perfect skin, and an IQ of 200 doesn’t mean there’s something wrong with me.

The world is a hard place, right now. Given that there are people I’ve never met, for whom I bear no ill-will, who want to destory me, my country, and my culture, I think I have a right, no let’s say a need, to be upset. Depressed, even. That’s a natural reaction, I’d say. I don’t want to treat it.

5

Thank goodness your’e only a freshperson. With this sort of reasoning we’ll all be afflicted with everything in a matter of minutes here. As a matter of fact, I eccchhhh :wink:

6

Oh dear. There are a few things to get out of the way, first:

  1. There is no “brain vs. mind.” You have a brain, it resides in your body, and your brain, body, nervous system, endocrine system, and most of the other systems all contribute to a swirling tableau of biochemical, electrochemical, and physical states, fluxes, gradients, and patterns. These are what we call consciousness. They are also the subconscious, the id, the ego, and all of those other words translated from German.

  2. Chemicals do not cause emotions. The patterns etc. described above are emotions. It’s a highly dynamic web of interactions, which always seems to be trembling on the edge of equilibrium, but somehow it almost always seems to return to a stable point (subjectively speaking). Sometimes, a small perturbation in the balance is experienced as an emotion; other times, as a thought, a memory, or a sensation.

  3. “Humans never stop feeling” Your prof is quite right. Nothing alive can turn off the pattern; nothing human can reduce the complexity and dynamism of the mind, because if it stops changing, it’s dead. Sometimes, the pattern is resistant to stimuli, which is what I think you mean. A sensation, a small jolt of nervous implulses, or a purely internal event which would normally be enough to significantly perturb the system just gets absorbed: depression. Sometimes this is due to unusually low levels of one or more components of the system; the one that seems to have been identified is serotonin. In other cases, pehaps some other component is too high.

  4. “Therapy doesn’t cure the cause” Nothing cures the cause; the cause is the system itself, and curing it would kill you. The antidepressants, as a class, have a crude effect on the balance of neurochemicals, and sometimes that’s just what’s needed. Sometimes, you need a hammer to fix something because it’s got a loose nail. Other times, it’s really a loose screw, and a hammer isn’t really the right tool, but until someone discovers a screwdriver, it’ll do–sort of. Other times, the hammer, the screwdriver, and the SSRI are irrelevant; the cause of depression is something complex, like an event (death in the family, financial crash, an injury, drug use), and crude elevations in serotonin do no good, and may do harm.

Remember: The pattern causes emotions; emotions and events are, in themselves, changes in the pattern, even in the physical arrangement of the brain itself. When an event causes an intense emotional reaction, it’s signified by intense changes in the pattern. Life-changing events can cause permanent changes in the equilibrium, changing attitudes, even the personality.

Similarly, psychotherapy, by causing repeated intense emotional events, changes the balance; successful psychotherapy changes it permanently. Because the balance correlates with mental state in each individual, therapy works for many people, even though the causes of their problems may be radically different.

  1. “Physiological depression isn’t universal” I don’t know what this means; if he’s saying that it’s not uniformly distributed among peoples, I’d reply (a) he has no way of knowing that–we can’t even accurately diagnose it among people rich enough to afford therapy; (b) why should it be? Physiological depression may actually be a social or cultural artifact, instead of a genetic one. The cause doesn’t change the nature of the problem, or the tools needed to repair it. It’s our limited understanding and our even more limited toolkit that causes the confusion.
7

BTW, you’re confusing “clinical depression” (depression severe enough to affect the ability to lead a normal life, and requiring treatment) with “physiological depression” (depression not associated with life events; thought to be due to ‘chemical imbalance’). Physiological depression can be clinical, or not; clinical depression can be physiological, or not.

8

It’s fascinating how these threads grow and change. If you asking for, as you say, exact medical causes for depression, the answer may, well, depress you. No one really knows. What you can use, however, is some ammunition for the battle against your philosophy professor. (By the way, these philosophy types are highly adept at pushing buttons. I think in past lives most of them were typists or frustrated controllers in nuclear weapons silos. So beware their game.)

Now we can argue about things like what constitutes depression, why one should or shouldn’t be depressed, and so forth. But when you meet someone who is profoundly depressed (what shrinks call Major Depression), all the philosophizing seems a bit moot and indulgent. Anyway, one of the prevailing ideas about the biological correlates, underpinnings, or whatever word you want to use, for depression has to do with, as Nametag says, a deficiency of serotonin action. What’s that? Well serotonin is one among many different kinds of neurotransmitters, which are what brain cells use to talk to each other. Brain cells squirt out small amounts of these chemicals, which then diffuse over to the next cell and influence how it responds. Then the neurotransmitter is taken back up (or shall we say reuptaken) into the cell that released it. Thus terminates its action until more is released. Now if you inhibit the reuptake of these chemicals, they are out and about and active for a longer time. This is the principle behind the so-called serotonin reuptake inhibitors (or SSRIs—the first S being for selective, for reasons which will be clear anon).

So why do people blame serotonin? The two main reasons, as far as I can tell, are (1) various experiments have shown a decreased amount of this chemical and its metabolites in the brains of depressed people and other animals (e won’t go into how these experiments were carried out); and (2) these serotonin reuptake inhibitors seem, by golly, to work. In fact, per my understanding, pretty much only drugs that somehow inhibit serotonin reuptake have been shown to convincingly make depressed people feel better. But, you say, Prozac and Zyprexa have only been around 10 years or so. That’s true, but even the old antidepressants worked by inhibiting serotonin reuptake. It’s just that they weren’t SELECTIVE, which meant they acted in many other areas as well as, it seems, the pertinent ones (whereever those are). This caused a lot of side effects (tiredness, weight gain, dizziness, etc). As far as efficacy is concerned, the newer SSRIs are no better than the older drugs- they’re just easier to handle side-effect wise. (A recent addendum to the story is the development of so called SSNRIs, which work by inhibiting the reuptake of serotonin and noradrenaline- another player).

Well, what is this serotonin doing, why is it so important? Again, it is not known for sure. One theory is that serotonin helps maintain the plasticity of neural circuits. Huh? Without going into a lot of detail, brain cells (or neurons) are arranged in circuits, interacting in the aforementioned manner. Patterns of activity through those circuits correlate (I’m deliberately trying to use a neutral word here) with mental activity. At the risk of digressing, this is, I believe, the main point of the book Why God Won’t Go Away. That is, those guys are saying that a particular pattern of brain activity can be correlated with mystical experiences. We’ll leave the arguments about causality to chicken and egg people for now. Some of these circuits are pretty much fixed. Say, that’s why people with certain brain injuries can not regain some abilities. Other of these circuits, particularly those that underlie, uh, I mean, correlate with, complex psychological experiences are probably pretty fluid, that is, plastic.

But back to depression—It’s thought that, maybe, in a depressed person, their neural circuits have arranged themselves in such a way that activity through those circuits produces (or correlates with) depressed feelings. What they need to do is rearrange those damn circuits. But telling them that is about as helpful as Ronald Regan telling them to pull themselves up by their bootstraps (dates me-depressing!). A sufficient amount of serotonin activity maybe necessary to keep the neural circuits loose enough to allow for rearranging. Thus, increasing its action allows them to in a happier manner.

But of course this does not work by chemicals alone. Experience, be it counseling, therapy, exercise, getting out and about, whatever, is also very instrumental in helping people get out of their funk. This is thought to be why antidepressants on their own do not work as well for more seriously depressed people as when they are used in combination with some sort of counseling or therapy That is, the extra serotonin action helps loosen the circuits, while the therapy helps people to see things from different angles, and thus nudges their neural circuits into a less depression-producing arrangement. But this is all speculative.

By the way, sickle cell disease is something a person is born with (i.e., it’s genetic). You can’t develop it later in life.

9

pepperlandgirl, your prof sounds like an idiot. Re: his remark that depression is “not universal,” I don’t know what he means, either, but there’s a book out called “The Noonday Demon – An Atlas of Depression” by Andrew Solomon. It deals with depression in other cultures, etc. and is supposed to be very good, maybe your prof should read it.