Green’s Dictionary of Slang

(US) foolish, stupid.

1923		E. O’Neill Hairy Ape Act I: Dat’s all a dope dream!
1938		Reading (PA) Eagle 20 Mar. 7/3: A ‘dope’ person is referred to as a ‘schmo hawk’.
1940		J.H. O’Hara Pal Joey 3: I was sorry if it embarrassed her me calling attention to her dope boyfriend.
2001		S. King Dreamcatcher 35: But man, that’s dope – he can’t read minds.