Serotonin Syndrome is a situation where there is an abundance of serotonin in your system and causing reactions (as listed below).
If you experience any of these symptoms, please get help right away.
The point here is that taking SSRI's (selective serotonin reuptake inhibitors) does come with adverse side effects, one being noteably called 'Serotonin Syndrom'.
This can happen when adding medications, or upping the dosage of your current medication. There have been cases of illicit drugs and dietary supplements impacting, thus increasing risk of this syndrome.
Here is a list of symptoms associated with Serotonin Syndrome (but not limited to):