jitters

As a former undergraduate psychology major, I was taught that the phrase "heebie jeebies" was a way of describing the behavior associated with Hebephrenic Schizophrenia. This sub-type of schizophrenia was named after the Greek goddess of youth, Hebe, due to the early onset of the disease in young adults.

Merriam-Webster online:
Pronunciation: "hE-bE-'jE-bEz
Function: noun plural
Etymology: coined by Billy DeBeck died 1942 American cartoonist
Date: 1923
JITTERS, CREEPS

Another source dates it to 1910 and says it was "popularized and probably coined by cartoonist William de Beck in his comic strip 'Barney Google.'" Listening to America: An Illustrated History of Words and Phrases from Our Lively and Splendid Past by Stuart Berg Flexner (Simon and Schuster, New York, 1982). Page 91. Maybe de Beck took a psych class or two?
"Flappers 2 Rappers: American Youth Slang" by Tom Dalzell (Merriam-Webster Inc., Springfield, Md., 1996), Page 15, places the expression during the 1920s flapper era. "After the stock market crash of 1929, 'jitters' replaced heebie-jeebies' as the slang expression of choice to convey extreme anxiety. Where 'jitters' came from is anyone's guess, but the supposition that it resulted from a spoonerism of gin and bitters (thus bin and gitters) and was thus applied to a state of alcoholism is as good a theory as any since 'jittersauce' was an established euphemism for alcohol during the Prohibition." Page 38.

And NOW I'm going to hear Little Richard singing Heeby-Jeebies all day: www.amazon.com/ Heres-Little-Richard/dp/B000GCG63W

[The OED says "origin unknown" of 'jitters' - but as a "supposition" the gin-and-bitters connection seems much too clever. Simpler to note that in the 1920s (and possibly earlier) "judder" was a frequent American vernacular form of "shudder," and from judder to jitter is an easy twitch of the playful American tongue. - Baceseras.]