The symptomatology of manic-depressive illness with its range of symptoms has been demonstrated above, in all cases with hereditary disposition. The essential feature is the manic and melancholic basic syndrome; atypical forms may be mixed states, or partial states, which occasionally mimic pure euphoria and depression, or an extension of the symptomatology into that of other bipolar forms. Certain similarities to cycloid psychoses can be understood as increase in degree of severity - thus confused mania and stuporous depressive pictures. The picture will be completed by the statistical results.

Certain points of view, however, which could be of clinical importance, are not being discussed here, since I have nothing new to add to them. I have no new results on the duration of the separate phases which, for mania, is considered to be about 3 to 6 months, and for melancholia about 6 to 9 months. My results also confirmed the fact that phases may exceptionally last only hours or continue for years and, in fact, become chronic. I have ignored normal temperaments associated with manic depressive disease, not because I saw no possibility of adding to our knowledge, but because special investigations were planned (Leonhard 1963 a and b, Leonhard et al. 1962, von Strostoff 1970). It is clear that hypomanic, hypomelancholic, and cyclothymic temperaments are present in the families of the patients as forms of dilutions of mania, melancholia, and manic-depressive mixed state. Beyond this, it is of great interest to what extent there are similarities with and differences from the temperament associated with other bipolar psychoses. Somatic findings in manic-depressive illness should be checked, if investigations thereof have been carried out in other phasic disorders.