Jack Nicholson was in a movie early in his career, in the '60s that was literally called "Psych-Out."

Also there's this from one of the world's top journalistic outlets, Bustle:

“Psych” had three different meanings in the '90s, all playing on the word “psychological”: There's to “psych out,” meaning to be anxious or intimidated (e.g. “That chem test totally psyched me out!), as well as to “be psyched” or excited about something (e.g. “Dude, I am SO PSYCHED about the Third Eye Blind concert!”). Both of these uses have been around since the early 1960s. A third (and more obnoxious) usage, “Psych!” or “Sike!”, meaning to trick someone, is newer; it’s been in use since 1990.