'After studying thousands of cases' of psychiatric war casualties, Greenson arrived at three distinct but by no means mutually exclusive categories of illness. (Incidentally, he notes that 'It is possible to see severe types of war neuroses in individuals who were formerly psychologically robust' and 'that many seriously neurotic and even psychotic individuals returned from severe combat stress relatively unscathed'.) He summarizes these categories with great clarity in a table which gives the clinical picture, therapy and prognosis of each type. Brief sketches of illustrative cases and their therapy are included in conjunction with a discussion of each category. In conclusion Greenson notes that 'The findings presented above do not contradict the expectations of the psychiatrist when he considers the important traumatic factors in the war situation. This new grouping is by no means to be considered complete or final, but it is intended to serve as a practical aid in brief psychotherapy based on psychodynamic principles.'