Joseph Wolpe (1915-1997) was a South African psychiatrist who worked as an army doctor helping patients who had been diagnosed with "war neurosis" (now called PTSD). His experience caused him to question the validity and usefulness of Freud's theories. Throughout the remainder of his career, he researched a treatment that he called "reciprocal inhibition." The primary thrust of this was assertiveness training as a means of controlling anxiety. This research led to to his development and use of "systematic desensitization". This is a process of slowly exposing a patient to the object that they are afraid of as a means of decreasing anxiety.