1930, from newspaper comic "Out Our Way" by U.S. cartoonist J.R. Williams (1888-1957), in which Worry Wart is attested by 1929. Worry Wart was a generic nickname or insult for any character who caused others to worry, which is the inverse of the current colloquial meaning. For example, from the comic printed in the Los Angeles Record, Dec. 5, 1929: One kid scolds another for driving a screw with a hammer "You doggone worry wart! Poundin' on a nut till it's buried inta th' table!" (etc.).