ɐ fˈoːɹθ ɪnstˈɔːlmənt, tˈaɪɾəld ɹˈɑːbɚt blˈɑːks sˈaɪkoʊ: sˌænɪtˈɛɹiəm ɹˈɪʔn̩ baɪ tʃˈɛt wˈɪljəmsən, wʌz ɹᵻlˈiːst ɪn tˈuː θˈaʊzənd sˈɪkstiːn.
A fourth installment, titled Robert Bloch's Psycho: Sanitarium written by Chet Williamson, was released in 2016.