You should watch:

The Schizoid Man

This was episode number 6 of season 2.

The following characters appeared in this episode:

(as W Morgan Sheppard)Dr Ira Graves

(uncredited)Crewmann/Security Guard

Captain Jean-Luc Picard

Counselor Deanna Troi

Commander Wiliam T Riker

Doctor Pulaski

Kareen Brianon

Lieutenant Geordi La Forge

Lieutenant Worf

Lt Commander Data/Dr Ira Graves

Lt Selar

Wesley Crusher