The automated diagnostic procedure appears to be particularly suitable for clinical psychopharmacological trials since it provides a diagnostic definition and a psychopathological profile of patients assessed by various investigators of different centers where a different kind of psychopathology as well as different cultural, clinical and psychopharmacological backgrounds may be present. Furthermore, this procedure offers the possibility of reexamining and analyzing the characteristics of the experimental sample as related to the responses to the drugs. It also provides a new approach for solving some of the problems which play an important role in determining divergent results in clinical psychopharmacology such as that of patients selection and diagnostic definition. In the present study the automated diagnostic procedure derived by the scores of each item of I.M.P.S. and by factor scores are evaluated comparatively. The data reported show that the automated diagnosis should be based on the scores of single aspects of the symptomatology rather than on the basis of the factor scores.