A retrospective study of 266 patients treated with neuroleptics and 130 patients treated with antidepressants divided the patients according to a global assessment after termination of therapy into responders and non-responders. The two groups were compared in respect to their psychopathological symptoms as assessed by the AMP system on days 0, 5, 10 and 20. Keeping the initial findings, comparable responders and non-responders showed statistically significant differences in the target syndrome from the 5th day onwards. The same applied to the findings on the 20th day (end result of treatment). The improvements found at the several points of testing, expressed as a percentage of the overall improvement after 20 days, show that the major part of the total improvement has taken place already after the first 10 days. The statistically significant changes were examined as to their practical relevance by giving their declared variance as a proportion of the total variance.