Serotonin almost stops during trauma/grief/depression, etc. That is normal, and the body starts producing it again soon. However, sometimes it seems to be unable to produce anymore. If it stays shut down, the depression you feel for legitimate reasons seems to never go away. There is nothing you can do about it - you can't "pull yourself up by your bootstraps" or "think happy thoughts" - just doesn't work. That's when anti-depressants are needed. They don't "give" you serotonin, but they kick start your body to hopefully start producing it by itself. Like throwing fertilizer on grass. Sometimes the Dr. has to experiment with which one to use - we're all different. But when you find the right one, it makes all the difference in the world. You may still have whatever your problems were, but at least now you're able to COPE. It saves lives.