Yes it does. If your brain produces less serotonin than others, you have what's called, 'clinical depression' and should be on an SSRI medication. I had that problem for 20 years. Was on a few SSRI's all those years, but things changed recently and now I don't need any of it. This could be temporary or the medication helped your brain learn how to produce more serotonin. Now if your brain produces too much, which is rare, but I've seen, those people are as hyper and giddy about everything but that can be fatal if its truly the brain producing too much
