In view of the particular problems of psychiatric classification the advantages and disadvantages of standardised rating scales are discussed. The result is that these instruments at present are irreplaceable in psychopathological research on behalf of their reliability in transmitting information and the possibility of quantifying psychopathological syndromes. The practice of 4 rating scales, which are still uncustomary mainly in the area of German language, is demonstrated by means of a psychopharmacological investigation example. These rating scales are: 1. the Hamilton Psychiatric Rating Scale for Depression, 2. the Wittenborn Psychiatric Rating Scale, 3. the Structured clinical Interview (Burdock and Hardesty) and 4. the Befindlichkeitsskala (Condition Scale) (v. Zerssen). Within a duration of treatment of 3 and 4 weeks desmethyl-loxapine [CL 67 772, 2-chloro-11-(1-piperazinyl)-dibenz (b,f)(1,4)-oxazepine] was tested in an open study as an antidepressant on 16 patients with different depressive syndromes. The results of treatment, which can be considered positive, are represented and discussed in an intra-individual pre- and after-treatment comparison in respect of the differences between these scales. The good therapeutic efficacy of desmethyl-loxapine results mainly from a marked anxiolytic effect. All the clinical and chemical examinations performed point out an excellent tolerance of this drug. German versions of standardised rating scales appear urgently indicated.