The answer isn't really known but current consensus is that it came from the author Rita Mae Brown in her book Sudden Death on Pg. 68 from 1983.
Quote: "Insanity is doing the same thing over and over again but expecting different results."
Most people will attribute this quote to Albert Einstein but there is no evidence to suggest that he made this statement.
This quote "Insanity is repeating the same mistakes and expecting different results" appears in the Basic Text of Narcotics Anonymous which was copyrighted in 1982 and later published in 1983. It is found on page 11 of the final "Review Form" which was distributed to the fellowship in November of 1981. It is found on page 23 of the current sixth edition.