Eli5: why is there no test for the “chemical imbalance” that is often mentioned for depression?
In: Chemistry
This is a billion dollar idea, anyone interested in making a machine doing this? Considering how prevalent depression is in modern society, the profit will be huge.
It’s because the “chemical imbalance” hypothesis is wrong. There are tests for how much serotonin is being processed through your brain. The results of those tests don’t predict whether someone is depressed or not.
Anyone else with depression not appreciate the quotation marks around chemical imbalance in OPs question?
Because it’s bullshit. You aren’t depressed because of a chemical imbalance. You are depressed because of some trauma in your life, or because you’re leading an unhappy life, possibly because we prioritise the wrong things, because we don’t have enough connection etc. The internet doesn’t make us more connected, it makes us less connected.
It is a simplification that doctors use to help people understand why drugs can help treat depression. The exact mechanisms behind depression are complex and poorly understood, and likely to vary from person to person. It seems to have something to do with neurotransmitters, and the receptors they bind to, and how they work to regulate each other. But testing for that would require knowing what the baseline is for that particular patient, and getting a sample would require a brain biopsy to examine local neurotrasmitter quantities as well as the density of their respective receptors. And we don’t know from where to take the biopsy and getting enough information may mean we would need to take several. And taking brain biopsies mean you cause local brain damage.
Functional MRI could be a non-invasive tool for determining overall brain metabolism in different functional areas and may eventually lead to more clues about what is wrong in the function of a depressed brain, possibly leading to diagnostic tests and personalized treatment opportunities, but we are a long way from that.
That is my understanding, as a medical doctor.
When we think about “chemical imbalance” and depression, those chemicals are mostly neurotransmitters. Neurotransmitters are made in the brain and they work between neurons which are tiny parts of the brain.
To test the number of neurotransmitters in the brain, we would have to take samples from inside the brain, which would be very difficult and dangerous because the brain is so delicate.
Another problem is that we don’t actually know much about the “chemical imbalance” explanation. It looks like it’s one part of the bigger puzzle, because a lot of people with depression benefit from medicines that affect that balance. Not all though. So even if we could measure how many neurotransmitters someone’s brain is making, using, and breaking up, we wouldn’t know what those numbers meant.
Neurotransmitter release not only varies in amount, but in timing, as bursts. The mix of these neurotransmitters differs in different parts of the brain and in response to different situations/actions.
So even if you COULD directly measure it, you’d have to do so over time, in various areas, in exposure to various different stimuli/situations.
And even if you could do THAT, it wouldn’t be helpful since epigenetics modifies the expression of genes in response to stress, making every human brain different.
Because there is no such thing. It was a term coined by psychologists in the 80s and 90s to sell the bipolar movement and people bough it.
Emotional baggage, unresolved traumas, when the mind is fed with shit the body starts feeling shit. When you are moving through life unaware of what your thinking feeling and not taking care of it stuff like this happens the power of thought is vastly underestimated
There’s a genetic test now which can be taken and conclude which will work best and which you should avoid. Why are doctors still making people be lab rats when the answers are clear?
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