You should watch:

The Quality of Life

This was episode number 9 of season 6.

The following characters appeared in this episode:

(credit only)Tyran
(uncredited) Ensign Jae
(voice) Enterprise Computer
Captain Jean-Luc Picard
Chief Kelso
Counselor Deanna Troi
Commander Wiliam T Riker
Doctor Beverly Crusher
Dr Farallon
Lieutenant Worf
Lt Commander Data
Lt Commander Geordi La Forge