When I talk about "horror movies," I'm usually talking about something with a supernatural elements--ghosts or demons or witches or vampires or something. But there's a whole level of movies without that element, movies that are terrible in a wholly human way. Hush...Hush Sweet Charlotte is a movie like that, an over-the-top melodramatic version of a psychological horror story starring two great actresses in the sunset of their careers. On IMDB, the movie is tagged as a drama/horror/thriller and it is all three of those.veryone remembers that Olivia de Havilland and Bette Davis starred in this movie about a southern belle gone looney, but most people don't remember that the movie was chock full of fabulous supporting actors including Agnes Moorehead, Bruce Dern, Cecil Kellaway, VictoBuono, and Joseph Cotton.You can watch the full movie on IMDB. 
I always associate this movie with What Ever Happened to Baby Jane, starring Bette Davis and Joan Crawford. I've always seen them together and my memory of them is so entwined that I can't remember which one had the moment where a boiled rat is served up for dinner. (I'm pretty sure that's Baby Jane). Baby Jane came out in 1962; Hush...Hush Sweet Charlotte came out in 1964. Both were directed by Robert Aldrich, who went on to direct The Dirty Dozen three years later. (Victor Buono co-starred in both movies, which was another connection between them.) Buono was only 43 when he died in 1982, and he was all over the landscape of the television shows I watched as a kid. 
