Beethoven's 9th symphony, 3rd movement.

4th movement when wishing to get tired or more stable, reset my mind, but not yet trying to sleep. The complexity is really breaking down expectations and a roller coaster more spectacular and varied than a mixed episode.

In general, also other, classical music. Beethoven (suspected BP, but based on the music alone clearly representing great emotional turmoil, with great differences between soft/smooth and erratic/manic/complex) primarily. No focus, manic flight of tones.

Edit:
Best music ever written (as "proof", just interesting: the original capacity of the CD is 74 minutes, exactly enough to fit the entire 9th symphony on one CD).

3rd movement really works as an anxiolytic if you just go with it. Taking in all long, smooth notes/harmony.

Another edit:
Oh, and if you are still wondering why it is really meant to represent mania, the choir:

"Joy! Beautiful godly sparks!", "All men will become brothers, where your wing touches" (text by Schiller). Romanticism being the way (manic-)depressives flourished.

But then now we know of course it is a disease and requires you to reach absolute compliance to all authority were you ever to manage. Never romanticise, never imagine.

History has depressive episodes as well. We're living one right now.