- Charlie Day (Charlie Kelly)
- Glenn Howerton (Dennis Reynolds)
- Rob Mac (Ronald 'Mac' McDonald)
- Kaitlin Olson (Dee Reynolds)
- Danny DeVito (Frank Reynolds)
It's Always Sunny in Philadelphia — S18E3
Episode: The Gang Gets Tested
Air Date: 2026-08-24
Overview
Dennis and Dee are diagnosed with ADHD, and even more shocking: Mac isn't. They go back to school for a do-over now that they understand their brains more better.