Chronic Pain Shrinks The Brain
An anonymous reader writes "LiveScience is reporting on a study showing that people with chronic lower back pain have 5 to 11 percent less gray matter than pain-free folks. Its not known for sure why, but the thinking is that neurons just get worn out as the mind deals with the pain."
If a system is inadequately evolved it would probably have to suffer through more pain to walk, jog, hunt, gather, etc.. By reducing the brain it could have a bigger impact on reproduction and survival. Perhaps we evolved a trait that helped one another evolve faster.
I'm inheriently distrustful of these studies, if simply because of the sheer number of flaws that could be present in their design. I remember, in the space of one week last year, hearing three different studies; "Eggs are good for you", "Eggs are bad for you" and finally back to "Eggs are good for you". Without huge problems in the study, they couldn't have come up with such disparate results. Take this with a grain of salt.
Shrinking grey matter causes chronic pain
Seriously, how do we know what the dependent variable is.
(and the flaming ensues)
You can remove the word "Pain" from the article title, and still have an accurate statement.
"You have smoked yourself retarded."
--riney
"Its not known for sure why, but the thinking is that neurons just get worn out as the mind deals with the pain."
Right. Either that or being stupid hurts.
There are no trails. There are no trees out here.
Taking painkillers constantly rots your brain.
Who could've guessed...
"I assumed blithely that there were no elves out there in the darkness"
He knew about the real cause way back in 1980!
.
- Preferences: Solaris 10 (servers), Ubuntu (desktops), Solaris 11 (personal servers) -
It just shrinks the short term memory. Like when you can't remember that you opened a bold tag only four words ago.
Possible causes? Perhaps the pain does cause the brain to shrink. Perhaps people who are predisposed to pain are also born with smaller brains. Perhaps their brains shrunk due to another cause and the shrinkage is causing the pain. Or perhaps with such a small study (26 people) they happened to choose people who just happened to have smaller amount of gray matter.
I would also like to note that brain functions that make humans able to reason more effectively are located in the gray matter part of the brain, which is the region that was found to be reduced. However, it is also known that the amount of gray matter is not strongly correlated with intelligence. (Actually, it has been found that the amount of folding, that is the number of creases on the brain, affects intelligence much more.) So, there is no reason yet to think that these people are actually suffering any loss of function.
So while interesting, until more research is done, these results should not be over-interpreted.
Perhaps it's not the pain that causes the brain to shrink, but rather while the brain is occupied with the constant pain it is unable to think about other things and grow?
Most of the method that others are complaining about (only 26 people, etc.--read the article, they're doing things just fine) seems fine to me, but what really bothers me is this:
They're claiming that a 30 cm^3 decrease is significant when their 1 sigma error is 42-44 cm^3! 1 sigma! In my field of science, nobody believes you unless the error bars don't overlap (much) with two or three sigma. Basically, everything is essentially the same to within one sigma:
528+44=572>569;
569-42=527528.
Anyway, I'm sure there's some stuff that I missed, but until a larger study is done with better error analysis, I'll take what they've done as probably correct, but with some doubt. . .