The state of mind after watching a scary movie. Symptoms include looking over the shoulder, checking under the bed, closing the curtains, anxiety of the dark and shadowy areas, sensitivity to sudden noise, and fears of normally non-scary objects (ie. television, dolls, clowns, etc.). The duration of this state of mind depends on how much of a chicken shit the person is.
"Don't bother her, she has a severe case of Scary Movie Syndrome."
"SMS is the cause of nightlight companies' success."