It IS basically the absolute opposite of euphoric hypomania! That's what puts the polar in bipolar!
Yup, a smile. It's not stupid or pollyanna. It's actually a bit like the way I envision fighting depression. Like this:

You take it further (in a good way!). I am only armed with the Sword of Baseline. You wield the (kick-azz, awesome, invincible, woohoo-bladed) Sword of Euphoric Hypomania!

Power to ya!
Hey, whatever we can duke it out with, right?