Evolution of Depression

[athon]

Oh, you people slay me.

I don't understand your comment. The quote makes perfect sense to me.

Athon

 

[Melendwyr]

For one thing, it implies that we have not yet discovered the cause of depression, and that we need to discover new, effective therapies.

If we already knew the cause of depression and possessed effective therapies, that would have been a rather odd thing to say, don't you think?

 

[brodski]

For one thing, it implies that we have not yet discovered the cause of depression, and that we need to discover new, effective therapies.

If we already knew the cause of depression and possessed effective therapies, that would have been a rather odd thing to say, don't you think?

and what exactly are these effective therapies?

 

[Skeptic Ginger]

I was checking out Bob Park's "What's New" column which is archived here, and noticed that there is new research. I did a search in the News and found it written up here:
http://www.thecrimson.com/article.aspx?ref=512936

Just thought you might be interested.

Major depressive episodes can be triggered by a major life event. The cortisol connection makes sense as a trigger anyway.

 

[Skeptic Ginger]

... why are you questioning it on account of 'similar genetics'. There's a lot of evidence supporting the fact that ADHD is due in part to genetic variation. Aborigines simply have a higher occurance of this variation. ...
Athon

If that is the case, then I have no issue. Any ethnic group can have a higher incidence of some genetic variation. It's only when you start to attribute broader behavioral or physical characteristics to a "race" that my skepticism increases.

I think we agree on the things discussed in this thread. I merely elaborated on some of them but wasn't disagreeing.

 

[Skeptic Ginger]

For one thing, it implies that we have not yet discovered the cause of depression, and that we need to discover new, effective therapies.

If we already knew the cause of depression and possessed effective therapies, that would have been a rather odd thing to say, don't you think?

Not if you are aware all forms of depression are not equal. The causes are many. Effective therapies exist but are not ideal for everyone with depression.

It isn't a simple black and white world, Melen.

 

[Melendwyr]

Still working on those sources.

 

[prewitt81]

Do hurry. The Jeopardy! theme has been going on for almost a month now.

 

[Jeff Corey]

...Given the way that the north american continent was settled I have wondered if that led to bipolar people leaving europe and moving to the US.

I don't know about that. In my background it was probably a choice between rotting in a debtors prison, being hung as a horsethief, starving in Ireland or the balmy Atlantic cruise. Depending upon where they originated.
I doubt they said, "OK, now all you bipolars, up the gangplank."

 

[prewitt81]

Still working on those sources.

It's been over a year now. Did you find anything?

 

[aggle-rithm]

What could be the evolutionary advantage of being able to suffer from depression? I'm not referring to clinical or severe depression, which would simply be an abnormal extension of 'normal' 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

I don't know if anyone's made this point, but here goes.

Depression in humans is often accompanied by low seritonin levels. Low seritonin is also a mark of adulthood in many (if not all) mammalian species. The result of lower seritonin levels in the wild is that adults are more cautious and aggressive than youngsters, and thus are given a clear survival advantage.

Humans are unusual in that they are pedomorphic (retain childlike attributes into adulthood), so low seritonin in human adults is maladaptive.

 

[Dancing David]

I don't know about that. In my background it was probably a choice between rotting in a debtors prison, being hung as a horsethief, starving in Ireland or the balmy Atlantic cruise. Depending upon where they originated.
I doubt they said, "OK, now all you bipolars, up the gangplank."

Quite understandable. I am just saying certain people would be more likely to roam. I am not aware of the Mood Disorder Cruise Line.

 

[Dancing David]

To the reason we might have mood disorders.

If you leave in higher latitudes having moods that adjust to the season could be useful.

When we look at the positive traits that run in families with depressed family member we may find a positive expression of a partial trait.

In my family there are a number of people with OCD featurtes and hypomania.

What leads to others to be successful, leads others to be not as successful.

 

[negativ]

Maybe that hunk would have been a better choice 10,000 years ago. In this era I'd have been better off with a rich brainy type.

Leave it to a depression thread to help me discover new and exciting reasons to feel suicidal.

I'm recently divorced, far from being a hunk ("hunk of refuse" notwithstanding), certainly not rich, and not especially brainy. What's left?

Man, being selected out of the gene pool sucks, especially when you can see it happening in real-time.

 

[athon]

I don't know if anyone's made this point, but here goes.

Depression in humans is often accompanied by low seritonin levels. Low seritonin is also a mark of adulthood in many (if not all) mammalian species. The result of lower seritonin levels in the wild is that adults are more cautious and aggressive than youngsters, and thus are given a clear survival advantage.

Humans are unusual in that they are pedomorphic (retain childlike attributes into adulthood), so low seritonin in human adults is maladaptive.

Hm, interesting. Thanks for pointing that out.

Athon

 

[John Hewitt]

I don't know if anyone's made this point, but here goes.

Depression in humans is often accompanied by low seritonin levels. Low seritonin is also a mark of adulthood in many (if not all) mammalian species. The result of lower seritonin levels in the wild is that adults are more cautious and aggressive than youngsters, and thus are given a clear survival advantage.

Humans are unusual in that they are pedomorphic (retain childlike attributes into adulthood), so low seritonin in human adults is maladaptive.

Also, possibly pertinent - I recall reading in cognitive and social psychology books that people who are feeling depressed perceive the world in a more objectively correct way than do people who are not depressed. (That is to say, they are less subject to biases of observation.) Is this correct and, if so, could depression be a means of driving people to change toward a more realistic appreciation of their situation in life?

 

[Professor Yaffle]

Completely anecdotal - but I suffer from recurrent depression and SAD, and I find it difficult to stay in work for any length of time. This has meant that I have been in less of a dilemma bout having kids than some of my friends who are very happy at work and more career focused. Even though they want to have kids, they have left it longer and therefore are more likely to suffer infertility. I also find that looking after my kids has helped to alleviate my depression, and am therefore considering having more kids than I might otherwise have done. Hence I pass my dysfunctional genes down to the next generation.

 

[Professor Yaffle]

Also, possibly pertinent - I recall reading in cognitive and social psychology books that people who are feeling depressed perceive the world in a more objectively correct way than do people who are not depressed. (That is to say, they are less subject to biases of observation.) Is this correct and, if so, could depression be a means of driving people to change toward a more realistic appreciation of their situation in life?

I think this research was flawed in that it looked at very mildly depressed students. It did indeed find that these people were more accurate in their perception of their own performance in a task, with "normal" people over estimating themselves. However, i think it was repeated in a more representative clinical population which found that more severely depressed people were just as inaccurate in under estimating their performance.

 

[Professor Yaffle]

I don't know if anyone's made this point, but here goes.

Depression in humans is often accompanied by low seritonin levels. Low seritonin is also a mark of adulthood in many (if not all) mammalian species. The result of lower seritonin levels in the wild is that adults are more cautious and aggressive than youngsters, and thus are given a clear survival advantage.

Humans are unusual in that they are pedomorphic (retain childlike attributes into adulthood), so low seritonin in human adults is maladaptive.

I think it is a little simplistic to think of depression purely as low serotonin levels and I am not even sure that this has been experimentally confirmed - rather just inferred from the type of drugs which have some success in treating depression. Someone with more current knowledge might be able to correct me if I am wrong. I thought the general idea was less about levels of serotonin per se, and more about individuals sensitivity to serotonin - ie that some people need more of the neurotransmitter than others because of this insensitivity.

Secondly, there are more neuro transmitters than serotonin that are implicated. SSRI's don't work on everyone with depression - myself included. I only get a benefit from drugs which alter noradrenalin (eg venlafaxine, mirtazepine, possibly some tricyclics). SSRIs have no effect on me.

Seratonin levels are not the whole story by any means.

ETA: Having just done a search of publications in the area, I have discovered that my understanding of serotonins role in depression is also hopelessly simplistic!

 

[andyandy]

something interesting in NS a couple of weeks ago...[i'll try to find it if others are interested]

was on how people with severe depression [with suicidal thoughts] have a serious impairment to their ability to imagine future events. That is to say, they can appreciate that future events will happen, but have an inability to place themselves in those events. It's as if the brain shuts down any long-term planning from a biological sense - and so the old adage "take one day at a time" as advice for coping with trauma, is actually enacted upon us by our brain chemistry.....