A friend wrote to me after the last Weekly(ish) asking, "What do I do if my fourth grader has an emotional break-down every time something doesn't go her way at home or with family?"
Lucky for my pal, I learned about this exact scenario from a super great therapist. Now, I'm happy to pass what I know to anyone else who has a kid who tends toward the hysterical. Here goes:
When your kid has a ridiculous reaction to a seemingly mundane event, breathe deeply and ask them to retreat to a quiet place to calm down. Then, when all is settled, say, "You know, I can tell you felt very strongly about X. It seemed to me that you felt [angry, sad, misunderstood, disappointed, etc.]" Wait for confirmation, which might take a long time or several tries.
Then say, "You know, there are lots of ways you can deal with [anger, sadness, misunderstanding, disappointment, etc.] One way is to cry and have a tantrum. That way seems like it's really hard for you. Would you like to work together to figure out some other strategies?"
To be honest, I've had some success and some failure with this technique. A certain young person in my household decided that he did actually prefer to have a full-on breakdown every morning at daycare and pre-k drop off. He even kept it up into Kindergarten. After about 24 months of using this cognitive processing protocol, he finally switched another method: a hug and a clear plan for after school pick up. It sounds good, though, doesn't it? Sometimes it works faster. Give it a try if you feel like it.