A Contribution to The Aetiology of Manic-Depressive Insanity (1940)

 Comparison with other Investigations

    I have considered it worth while to compare my results with those of Röll and Entres.1 For this purpose it was necessary to recalculate their figures by the Strömgren method (see Table 26). The statistical significance of differences found can be tested by the formula

and it is clear that there is only one place in the table where a difference of any significance is apparent, i.e. the frequency of schizophrenia among the female children. Here the difference is slightly over twice its standard deviation and so cannot be regard­ed as having attained a high degree of significance. One may con­clude therefore that there is no essential difference between t result of Röll and Entres and of myself, caused either by differ­ences of the original matefial or of its treatment (particularly the standards of diagnosis of the secondary cases). One must therefore admit that my attempt to select a special group of manic­depressives has failed; and this in itself suggests the conclusion that the propositi I selected, a group of a more obviously endogenous type, in every way correspond in genotypic constitution to the generality of manic‑depressives.

    I would have like to have worked over the material published by Hoffmann.2 From the clinical data he gives it is clear that his standards of diagnosis for the seconaarr cases in his manic‑depressive families are quite different from the standards used by Röll and Entres and myself. Hoffmann classifies as manic‑depressives quite a number of persons whom I should at most regard as persons of psychopathic constitution with swings of mood. It would therefore be necessary to re‑diagnose all his cases with the aid of the very sparing clinical data he provides. In my opinion, the results would not be sufficiently reliable for this to be worth doing. The interesting work of Weinberg and Lobstein3 is a report on a Jewish material which is not directly comparable with my own. According to these authors, the frequency of manic‑depressive psychoses in the parents and children of their propositi is 9.2% and 4.8%. Unfortunately, however, their statistical operations are not clearly described and these figures would not appear to be comparable with my results. Furthermore, as their tables are arranged quite differently from the methods of tabulation employed by Röll and Entres and myself, it is not possible to recalculate their results by what I would regard as more satisfactory methods.

(1) Z. ges. Neuol. Psychiat. (1936) 156.
(2) Monor. Neur. (1921) 26.
(3) Psychiat. Bl. (Dutch) (1936) 1a.