Denne vigtige undersøgelse er set i
Forsknings-nyt fra psykologien
hvor Thomas Nielsen skriver:
"Et af de mest omtalte signalstoffer i hjernen er serotonin,
som især er blevet berømt på grund af de såkaldte "lykkepiller",
der kan dæmpe depressive lidelser. Ulykkepiller har den virkning
at de forøger effekten af den serotonin der er, således at der kommer
bedre gang i de hjernedele, der bruger dette signalstof.
Fra dyreforsøg ved vi, at serotonin er velegnet til
at dæmpe en følelsesmæssig ophidselse, hvilket passer ganske godt med,
at en depression oftest opstår efter en periode med mange "slag" i tilværelsen,
som hos nogle mennesker fremkalder så stærke og langvarige negative følelser,
at de helt opgiver ævred og synker ned i en mere eller mindre dyb depression.
Denne depressive tilstand kan i nogle tilfælde modvirkes af (u)lykkepillerne,
der øger serotoninniveauet, hvilket dæmper de stærke negative følelser.
Undersøgelser over vore nærmeste fætre i dyreriget, de store menneskeaber,
har vist, at de aber der fra naturens side har et lavt serotoninindhold i hjernen,
også er de, der reagerer mest følelsesmæssigt ophidset f. eks. med angst
eller aggression, når der sker noget ubehageligt, samt at man også
hos disse dyr kan dæmpe denne ophidselse med "lykkepiller".
Det er dog endnu mere interessant,
at man ved undersøgelser over hele abekolonier har kunnet konstatere,
at de aber, der "undertrykkes" i det sociale hieraki og som mister social status,
derefter får mindre seroton i hjernen. Denne kemiske ændring kan
derfor godt opfattes som en reaktion på en "social undertrykkelse".
Nu viser en ny undersøgelse fra Universitetet i Pittsburgh,
at dette serotonintab muligvis også gør sig gældende for mennesker!
De amerikanske forskere udsatte 270 voksne mennesker fra alle lag i samfundet
for en test, der indirekte gav et konkret mål for serotoninindholdet i deres hjerner'.
Det viste sig nu - ikke særlig overraskende - at der var en nær sammenhæng
mellem de pågældendes svar på et spørgeskema vedr. deres oplevelse af angst
og vrede på den ene side - og deres serotonin-indhold i hjernen på den anden side.
Det nye - som var mere overraskende - viste sig at være,
at der også var en tydelig sammenhæng mellem den sociale status i hierakiet
og serotoninindholdet: Således at de, der var havnet i de lavere lag af samfundet,
også havde et langt mindre serotoninindhold i hjernen, sammenlignet med de,
som var steget til tops i samfundshierarkiet og havde store stillinger.
Og forskerne kunne endda påvise, at det ikke bare var,
fordi at de "lavtstillede" i samfundet var mere ængstelige eller deprimerede,
at de havde et lavt serotoninindhold i hjernen! Også de lavtstillede, der ikke var plagede
af følelsesmæssige problemer, havde et gennemsnitligt lavere serotonin-indhold
end de, som både havde en højere løn og højere status i hierakiet.
Konklusionen af undersøgelserne er,
at dette sandsynligvis også gælder for mennesker,
således at det netop er de som "undertrykkes" i det sociale hierarki,
der får det laveste serotoninindhold i hjernen.
Hvilket jo burde mane til eftertanke
og give depressionsdebatten en ny dimension.
Thomas Nielsen, er lektor på Psykologisk Institut, Århus.
Referatet er fra: Forsknings-nyt fra psykologien, 2001, 10 (4)
Kilde: Matdiews, K.A., Flory, J.D., Muldoon, M.F., & Manuck, S.B. (2000),
Does Socioeconornie Status Relate to Central Serotonergic Responsivity in Healthy Adults ?
Set i Psychosomatie Medicine, 62, 231 - 237.
+ i det interessante webtidsskrift HMS Beagle,
så jeg den 11. maj, 2001 denne suplerende artikel om
sammenhængen imellem tab af status i flokken og depression,
(som jeg vil blive glad for om en gad oversætte til dansk, TAK!)
I dont get mad, I get even.
Actually, I dont get even, I usually get mad.
Okay, really, I just get depressed and mourn for a while.
Then eventually, after much pain and consideration, I get over it.
Kort fortalt handler ariklen om:
"Evolutionary theories of depression attempt the difficult task
of explaining, why such a debilitating disorder could at one time
have been advantageous to our survival. This might offer new insights
into new treatments and understanding.
Evolutionary Psychology by Maia Szalavitz
Posted May 11, 2001 · Issue 102, HMS Beagle
"Anyone who has suffered from depression, or watched a loved one
struggle with its paralyzing pleasurelessness and hopeless moods, may find
it hard to believe that such a black state could be an evolutionary adaptation.
How could a Darwinian selection favor the black dog?
Evolutionary psychologists have several overlapping theories.
While they stress that not all depression is adaptive, and that something
that was adaptive in the Paleolithic may not be so useful now, all believe
that understanding the syndromes evolutionary origins could improve
both psychotherapeutic talking and pharmacological therapies.
Based on observation of both humans and nonhuman primates
with hierarchical social structures, John Price, an English psychiatrist (now retired),
proposed in 1972 that depression serves as a submission signal. When an animal suffers
a defeat and slides down the hierarchy, stress hormones rise and serotonin levels fall
- a chemical signature of most depression.
Depression makes people feel inferior, says Price.
It makes them feel that a low rank is appropriate, so that they behave accordingly.
The important thing to grasp is that the basis of mood change is
to alter strategies of escalation and de-escalation in competitions.
Price points out that mood often shifts independently of rational thought.
A patient may be suffering because at the top level [his rational thoughts and plans],
he is escalating his competitive strategy, but he is not winning; the experience of being insulted
or struck gets through to his emotional brain, which decides to de-escalate.
Depression can be adaptive,
Price says, it removes an animal or person from a losing situation.
By showing signs of submission and withdrawal, the animal can avoid the danger
of being injured by a dominant individual and can wait to fight for resources
or mates - until it has a better chance of winning.
Paul Gilbert, professor of clinical psychology
at the Institute of Behavioural Sciences of Derby University in England,
notes that the submission theory accounts for the way anxiety and depression
are often inextricably linked. Lower-ranking animals have stress from above,
They need to be more anxious and wary because otherwise they get in trouble.
They need lower confidence, because non-anxious subordinates get pounded.
This theory also sheds light on the connection between depression and low self-esteem.
Depressed people are more withdrawn and they dont feel as lovable, attractive, etc.
as others, says Gilbert.
The idea that depression is anger turned inward also fits with this:
Depressed people often bottle up their anger toward their superiors and take it out
on themselves, although they may also express more rage and hostility toward those
below them on the totem pole.
Gilbert points out that inescapable stress can often contribute to depression.
An animal with social stresses can get away, he can avoid the dominants; but human society
often traps people. A human who is being abused by a boss or spouse is not always able to escape.
Abused children are trapped in just such a situation
- and the abuse constantly tells them that they are worthless and inferior.
Not surprisingly, having been abused puts people at high risk for depression.
Psychologists - starting with Martin Seligman - have shown that it is the lack of control
over a situation that helps stress create depression. Says Gilbert, Chronic, inescapable stress
does bad things to you. Like diarrhea and vomiting, stress hormones are useful
in the short term, but for any length of time they do real harm.
Studies have shown that high doses of stress hormones
actually damage brain cells in the hippocampus - and interestingly,
antidepressants seem to stimulate the release of nerve growth factors in this region.
Researchers have recently been looking beyond neurotransmitters and into hormones
and growth factors as possible areas of intervention for depression.
An ongoing study of thousands of British civil servants has found
that the health effects of rank arent limited to psychiatry. Lower-ranking employees
have higher levels of coronary artery disease and chronic bronchitis as well as depression
- and low status has an even stronger deleterious effect on health than does smoking.
For humans, unlike other animals, theres the added problem
that they can obsess about their status and this can reinforce the physiology of depression.
Says Gilbert, Imagine you are lying in bed thinking sexual thoughts. Your own fantasies
can generate hormones and arousal. But what happens if you are ruminating
and fantasizing that you have no future, that you are inferior?
It simply rocket up your stress hormones.
Gilbert doesnt see this self-reinforcing aspect of depression as adaptive,
and believes that medications are often crucial to changing the physiological climate of the brain
to allow more positive thoughts to arise. Cognitive therapies can then help the person develop
a better strategy to cope with competition - either by working on ways to win
or by finding ways to shift to more attainable goals.
Price agrees, but has some concerns about using medications in all circumstances.
He cites the example of a depressed farmer he treated, who was in conflict with his son
about the future direction of the farm. While depressed, the father resigned himself
to ceding control over the property.
But I dont know what would have happened
if we had given him antidepressants first, whether he would have gotten more stubborn
and made the situation worse, Price says. The function of depression, as I see it, is to get people
to give up unwinnable fights - until they give up, it has a function, Price concludes.
Gilbert says there is not enough research to determine whether antidepressants
tend to make people fight longer for the unattainable - or move on. To be honest,
I dont think it is well studied, he says. He suggests that someone should study
whether people in bad marriages who take antidepressants are more likely
to stay with their spouses because the drugs make it bearable,
or to leave because the drugs give them new confidence.
Its a question worth asking.
Unprompted, University of Michigan psychiatry professor Randolph Nesse,
director of the Evolution and Human Adaptation Program at the universitys Institute
for Social Research and originator of a broader evolutionary theory on depression,
suggests the same experiment. My clinical guess is that they are much more
likely to get out, he says.
Nesses theory suggests that depression doesnt have just one function;
rather, mood is related to how well goals (whether status-related or not)
are the current life strategy or a switch to a new one. Says Nesse,
Some depression may be tied up with the role of mood
in regulating behavior when you are pursuing a goal you cant reach.
The motivation to stop or get out grows, just as your motivation to breathe grows
when you hold your breath. The system is trying to get you to stop doing something,
but you put more and more effort into doing it. If the mechanism works, he continues,
The bad feeling goes away when you change your goal. The deep problem with the theory
that depression is useful is that then why doesnt it get you out of the bad situation?
Nesse speculates that depression may be paralyzing
because our ancestors may have faced many situations in which giving up too soon
and starting something new immediately was disadvantageous; hence a syndrome
which retards almost all action.
Nesse stresses, however, that a lot of depression is disease.
People think that evolutionary approaches involve treating people like animals,
but this kind of evolutionary approach encourages great attention to individuals,
to their lives and loves and whats meaningful to them. It gets us back to meaningful contact.
Medications are useful, he believes, but should not just be handed out
without further thought.
One type of depression that may have a particular adaptive function
is postpartum depression (PPD). The evolutionary problem in the case
of postpartum depression is, whether or not to invest in this particular child,
says Ed Hagen, a postdoc studying the condition at the University of California at Santa Barbara.
It is very clear that mothers and fathers do make a decision of this sort.
Important factors in the decision for the mother are how healthy is this baby,
how many kids do I already have, and how much support is there from the father and others.
All of these factors are related to the incidence of PPD.
Studies find that the less support a woman has and the less healthy
she perceives a baby to be, the higher her likelihood of suffering PPD.
Early in evolutionary history, infanticide was a common solution
- and those who chose it appropriately may have been more likely ultimately
to have greater numbers of surviving children. Modern society, of course,
strongly stigmatizes infanticide, often with legal penalties.
If it is indecision over investment
- rather than unhappiness over abandoning the child
that causes depression, one would predict that the incidence of PPD
in hunter-gatherers would be relatively low; but as yet there is no data on this question.
Hagen sees PPD as a test case for theories of depression in general,
which he views as a negotiating tactic, not a signal of submission. Its plausible
to suggest that if mothers are constrained and cant just walk away, their only strategy
to get others to invest more in [a] child is to go on strike and say [via the depression],
If you dont help me, I wont do anything.
Its a last-ditch strategy; its completely unconscious, and not deliberate or manipulative, he says.
Hagen finds that PPD does cause others to invest more - the father and other relatives
almost always increase support for mother and child in such situations.
My clinical impression is that if the mother is assertive
and negotiates support before the baby is born, there is a lower chance of PPD.
He sees some support for the status theory, but says, The threat of suicide doesnt make sense
in a submission model, but it does in a bargaining model. If Im a mother, I offer the benefit
of caring for the new child, existing children, future children - and if I die or defect,
thats all gone, so youd better change [and help out].
Opponents of the idea of depression as bargaining
say that the condition is so unattractive that it can just as easily have the effect
of pushing people away as attracting help. Hagen acknowledges this, and says,
Its a hardball negotiating tactic, yes - it is a last resort.
As far as PPD treatment strategies are concerned,
the bargaining idea suggests that involving other family members in therapy
and helping the mother learn to assert her needs would be useful.
Though skeptics may see evolutionary theories of depression
as adaptationism gone overboard, they are certainly far less outlandish
than many Freudian ideas that still pervade psychology. At least more research here
could offer practical answers to questions about the social effects of antidepressants
- and perhaps new ideas for medications and talk therapy development.
Maia Szalavitz is a health/science journalist
who has written for the New York Times, the Washington Post, Newsday,
New York Magazine, Salon, and other major publications.
fra HMS Beagles-issue 102, 14 - 5 - 2001