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

 Conclusions

1.  The age incidence of manic‑depressive insanity has been examined for males and females ad exact values of the relative frequencies for every year of life have been calculated. The high­est incidence occurs in both sexes between the ages of 30 and 60.

2.  Manic‑depressive illnesses show a seasonal variation, being most common in the early summer.

3.  Individual manic‑depressives have their own preferred season of the year for falling ill.

4.  Individual manic‑depressives have their individual rhythms, and having fallen ill once have a tendency to fall ill again after the passage of a certain period.

5.  There is no general tendency for lengths of remission to become shorter as attacks of illness recur.

6.  The manic‑depressive constitution appears to be related to a familial arteriopathic tendency.

7.  The manic‑depressive constitution is not associated with a low social level, nor does the occurrence of the psychosis in a family appear to cause a fall in the level.

8.  The frequency of manic‑depressive insanity among the parents of manic‑depressives is 11.5%, among their children 22.2%. These figures are approximate and subject to large errors. They are in agreement with the findings of other investigators.

9.  The expectation of manic‑depressive insanity in the general population is for males 0.36% ± 0.16%, for females 0.38% ± 0.11%.

10. A familial tendency to manic‑depressive insanity is not asso­ciated with a tendency to any other psychiatric anomaly, with thepossible exception of schizophrenia.

11. The majority of schizophrenic psychoses occurring in manic­depressive families show affective and cyclic features.

12. The inheritance of manic‑depressive insanity is of the dominant type and is quite probably due to a single dominant autosomal gene with a low rate of manifestation.

Appendix

    For the original idea that it wold he north seeing whether one could sift out of the general run of manic‑depressives a special group which would show a specific and independent type of inheritance, I am indebted to Dr. Aubrey Lewis.   

    For the permission to carry out this idea with the enormous technical and administrative advantages of the German Psychiatric Research Institute in Munich, for secretarial help and other ass­istance (e.g. from the Director o the Eglfing Hospital), I am indebted to Herr Professor Dr. E. Rüdin.

     For practical assistance, particularly in the earlier stages, in dealing with German informants and clinical material and for lasting encouragement and advice, I am indebted to Dr. Bruno Schulz.

    For checking over my conclusions as to the appropriate dia­gnosis to he made on some of the secondary cases of insanity dis­covered in the course of the investigation, I am indebted to Drs. W. Mayer‑Gross and E. Guttmann.

    For advice as to the appropriate statistical methods to employ in Sections I (d) and (e), I am indebted to Dr. J. O. Irwin.

    For financial support during the work in Germany, I am indebted to the Rockefeller Foundation.