A specific question, answered specifically.

ADHD task-switching cost — the real numbers and the fix

The most-cited number for task switching is from Gloria Mark's research at UC Irvine: average knowledge worker is interrupted every 11 minutes, and it takes 23 minutes to fully recover focus. The ADHD modifier on that 23 is poorly studied but anecdotally significantly higher — closer to 35-45 minutes for context-heavy tasks.

This is the actual reason you "didn't get anything done today." It's not that you didn't work. You worked seven 11-minute blocks separated by six 30-minute recovery periods. That's 4 hours of "work" with maybe 80 minutes of actual output. The longer-form version of the mechanic is in what is task switching cost and how to reduce it.

What actually works

Two-hour deep blocks, scheduled. Not aspirational — on the calendar. Phone in another room. Slack closed. Notifications off.

Single-tab discipline during the block. If you need a reference tab, fine. If you have 14, you're not in a deep block, you're in a research swirl.

A pair of Loop Quiet earplugs at $4.99-32. Drop ambient noise enough that the open-plan coffee shop becomes workable. Not magic — they don't block voices well — but they reduce the involuntary attention-shift rate measurably.

What doesn't work

"Just don't get distracted." Useful if you have working dopamine regulation, which you don't.

Apps that block other apps. They help for 9 days, then you uninstall them or override them. The block apps treat the symptom.

Multitasking. There is no such thing. There is only fast switching, and you pay 23+ minutes per switch. The buffer-side cost is in ADHD working memory limits.

The Deskrune version

The ADHD EF Kit has a deep-block scheduler — picks two 90-minute blocks per week and assigns them to a specific project. Not seven blocks; two. Two real blocks beat seven aspirational ones. $4.99 through May 31.