I took a "mood improving" probiotic for a few days and forgot to take it yesterday. Today, my mood is absolutely awful. I just want to lay in bed and cry. Is this possible withdrawl? If so, this could be dangerous for people with suicidal thoughts who seek probiotics as an alternative to Rx treatment. This is the second time this has happened after taking those supplements which is why I think the two events are related. Be careful taking mood altering supplements.