Started filming a month before Psycho...

on October 12th, 1959 (Psycho started filming on November 11, 1959), but it was not released until a three months after Psycho (released in June 16th, 1960) in September of 1960.

There is an undeniable similarity between the fates of the two "heroines" in both films, and the ending of the film with Mrs. Newlys/Selwyn is very reminiscent of "mother" in the fruit cellar. Apparently, though, it was just a coincidence.