How do serotonin levels change when it has to make friends elsewhere?

I can't sleep, so what else to do. On Reddit, in one (non)specific subreddit, this question is asked relatively often. Mostly in the context of people being afraid to start antidepressants precisely because of their difficult beginnings and fearing that it will be permanent - the fear of weight gain, fatigue, emotional blunting, etc. All these feelings are completely justified. What is often…