Complex sentence: Since then, psychoanalysis has expanded, it has been revised, reformed and developed in different directions, first by Freud's colleagues and students, such as Alfred Adler and Carl Gustav Jung who went on to develop own ideas independently from Freud.
Split into simpler sentences: Since then, psychoanalysis has expanded and been revised, reformed and developed in different directions. This was initially by Freud's colleagues and students, such as Alfred Adler and Carl Gustav Jung who went on to develop their own ideas independently from Freud.