Bloch's other 'Psycho'-film, The Psychopath (1966)
It's well-known that Robert Bloch was irked both by his not sharing financially in Psycho's success beyond his original $9K rights to the story, and by Stefano's screenplay getting a lot of the reflected glory and career push from the success.
This led directly to Bloch concentrating on screenwriting, notably for Alfred Hitchcock Presents and Hour, Star Trek, and quite a few movies. Two of the films in particular are pretty naked attempts to re-capture Psycho's magic. The first, William Castle's Strait-jacket (1964), has been discussed a number of times on this board and its IMDb ancestor, but the second, Freddie Francis's The Psychopath (1966), hereafter P-66, hasn't been discussed that I can recall. Presumably this is largely because P-66, never much of a hit, has always been quite hard to see. While it was around on vhs (vastly cropped from its wide-screen), P-66 never got a dvd release. The film's fortunes have greatly improved in 2018, however, since P-66 has been released on a high-quality blu-ray. The picture is widescreen, has been restored as far as possible. Quite a few vertical lines mar the image especially near the beginning of the film - I suspect that they've had to stitch together and restore in part from widescreen prints for which there was no negative - but otherwise this is a pretty jolly good image. A commentary track is provided that explores the connections between P-66 and early Giallo, e.g., Bava's Blood and Black Lace. P-66 did its strongest business in Italy where they were alive to all these knowing references.