[Methodological problems of the clinical research on rhythms in depressive patients (author's transl)].

The working hypothesis is discussed that desynchronized rhythmic functions are at the root of endogenous depression. Methods and problems of the clinical research on rhythms in depressives are concerned with the assessment of data, experimental conditions, technical procedures and the personality of the depressive patient in his predicament. Investigations of groups of patients are considered critically, the necessity of intraindividual long-term studies is emphasized.