A phrase used to describe the feeling of depression that comes onto someone when they least expect it and is usually due to many unfortunate and/or negative things happening to the person who is feeling depressed. It usually does a lot of damage emotionally and can result in a massive mood swing for the depressee. The Espresso part is made up of the words express and espresso. It refers to the sudden draining feeling you get after drinking a highly caffeinated drink such as an Espresso (relatable to that of an Expresso Depresso type meltdown) and the fact that the depressed feeling comes really quickly (almost like express delivery!). The depresso part is the word depression, manipulated to sound better/rhyme with the word Expresso.
Jasmin: I'm feeling SO Expresso Depresso right now.
Hayley: Why what happened?
Jasmin: Well I was fine this morning until my boyfriend and I got into ANOTHER fight, I failed my math test, and there's a new rumour being spread about me.
Hayley: Gosh, that IS depressing... :(