5 ms·

I'm curious what happens if the markers are removed. For example, if one of the markers is that you've got too much X in your system, and you take a drug that

by zoba 12y ago

I'm curious what happens if the markers are removed. For example, if one of the markers is that you've got too much X in your system, and you take a drug that binds to X and then is flushed out of your system - do you stay depressed?

ufo 12y ago
I doubt it would help as those mmarkers are more likely an innocuous byproduct than a cause of the problem. RNA is something that does its job inside the cells and I'm actually surprised that they can get useful markers from blood.
lutusp 12y ago
Not likely. Many of these indicators are tangentially related to depression, they're not causative agents -- or we don't know enough to be able to make that claim. This may seem to be a trite example, but many diseases are accompanied by a fever. But treating the fever doesn't treat the disease, and in some cases you're better of letting the fever abate on its own.
gwern 12y ago
Almost certainly not. Biological systems are deeply complicated intertangled nests of cause and effect; when you measure a correlation between two variables (such as being depressed and lower/higher levels of RNA X), it's not going to be a direct causal link, you're much more likely to have picked up on a distant indirect relationship. (I have an essay on this topic which you might have seen on HN before: http://gwern.net/Causality http://gwern.net/Causality ) In this case, if you skim the depression literature, you'll find depression linked with all sorts of things - too much sleep, too little sleep, weight changes, poorer cognitive performance, high inflammation levels, bad eating habits, stimulants, etc etc. Any of these could be a good predictor of depression but changing them will not help or may harm. (If a depressed person finds modafinil helps them get through the day, a naive investigator may find modafinil correlates with depression - and take it away. Not going to help.)

by zoba 12y ago

ufo 12y ago

I doubt it would help as those mmarkers are more likely an innocuous byproduct than a cause of the problem. RNA is something that does its job inside the cells and I'm actually surprised that they can get useful markers from blood.

lutusp 12y ago

Not likely. Many of these indicators are tangentially related to depression, they're not causative agents -- or we don't know enough to be able to make that claim. This may seem to be a trite example, but many diseases are accompanied by a fever. But treating the fever doesn't treat the disease, and in some cases you're better of letting the fever abate on its own.

gwern 12y ago

Almost certainly not. Biological systems are deeply complicated intertangled nests of cause and effect; when you measure a correlation between two variables (such as being depressed and lower/higher levels of RNA X), it's not going to be a direct causal link, you're much more likely to have picked up on a distant indirect relationship. (I have an essay on this topic which you might have seen on HN before: http://gwern.net/Causality http://gwern.net/Causality ) In this case, if you skim the depression literature, you'll find depression linked with all sorts of things - too much sleep, too little sleep, weight changes, poorer cognitive performance, high inflammation levels, bad eating habits, stimulants, etc etc. Any of these could be a good predictor of depression but changing them will not help or may harm. (If a depressed person finds modafinil helps them get through the day, a naive investigator may find modafinil correlates with depression - and take it away. Not going to help.)