[Family constellation in mental disorder. results and methods of statistical investigations of family size, birth order and sib position (author's transl)].

Possibilities, difficulties and results of statistic investigations on the relation between schizophrenia, depression, neurosis and alcoholism are reported: The schizophrenic patients showed an excess of single childs and children of large sibship. In depressive patients the eldest are overrepresented. In neurotics single and eldest children are more numerous than in the general population. In alcoholic males tha last born und specially the youngest children are overrepresented. But nearly al of the relations found here have been contested by some other authors. The results are different because of the different methods. The reasons are explained in the second part of this study. The methodical differences consist in variable diagnosis, inadmissible selection, investigation without direct interviews, different statistical methods, summation of heterogenous samples and nonrepresentative controls. Methodical consequences for further investigations are discussed.