Howard Avedis Occupational Therapist Director, Actor, Producer, Writer Bo Hopkins Carl Actor Dianne Hull Kelly McIntyre Actor Patti D'Arbanville Cathy Actor Sharon Farrell Melanie Actor Mel Ferrer Dr. Sidney Coleman Actor Julie Adams Nurse Hannelord Actor John David Carson Ronnie Denton Actor Patti Brooks Disco Singer Actor Robert Englund Benny Actor Anthony James Derrick Actor Earl Boen Phil Actor Betty Kean Sophy Actor Alice Nunn Emma Actor Cathey Paine Lois Actor Udana Power Nurse Whelan Actor Maggie Appel Mental Patient Actor Gregory J. Barnett Deputy Sheriff Actor Michael Berryman Mental Patient Actor Chuck Boyd Douglas Crawford Actor Pattie Brooks Disco Singer, Mental Patient, Dr. Morgan Actor, Actor, Actor Bob Herron Sheriff Actor Peter Horak Driver Actor M.G. Kelly Hal Actor Milt Kogan Dr. Shaw Actor Suzanne Niles Doreen Actor Mary Ellen O'Neill Mental Patient Actor Grant Owens Jerry Actor Marlene Schmidt Night Nurse Actor, Executive Producer, Writer Lee Stein Lou Actor Duane Tucker Psych Tech Actor Tracey Walter Mental Patient Actor Michael Adams Screenwriter Daniel Pearl Cinematographer Stanford C. Allen Film Editing Alan Silvestri Original Music Chuck Seaton Art Director Bill Kawata Associate Producer