> If depression is just an imbalance, it may be that there is either too much serotonin or too little. Depression is a heterogeneous condition. The "truth" is

> If depression is just an imbalance, it may be that there is either too much serotonin or too little. Depression is a heterogeneous condition. The "truth" is that it's probably not one, but several conditions with similar symptoms; we just don't have the means to distinguish between them yet. So, we (ie, psychiatrists) try different medications that are known to work on some subset of depression patients, and hope that we find one that fits. I think this is part of why psychiatry gets a bad reputation - even when practiced well, it's an attempt to develop a model for one of the most complicated systems in existence: the human mind & body. When you think about it like that, it's almost a miracle that we're able to do anything given our limited understanding of the way the mind works. (With many medications, we know what chemical effect the medicine has, and we know what subjective effect the medicine has, but we actually don't have a solid understanding of the link between those two). But that's not an indictment of the field as a whole, just an observation of how much more we have yet to learn.