I'm still trying to figure out what "triggers" a depressive episode with me, but a few things to definitely stomp my mood into the ground pretty quick are:

1. Talking to my ex. In any capacity. Literally even if we're just talking nicely like we do nowadays, I spent too many years being yelled at and put down and my brain is still getting over it.
2. Getting caught in the thought cycle of being a "bad mom".

That's all I know for sure right now...