The Question of Endogenous Mixed Psychosis

Abstract

For many years the psychiatric literature has contained articles on mixed psychoses. It was assumed that schizophrenia as an entity was not infrequently combined with manic-depressive illness; the symptom picture and course of the disorder showed a mixture of both components. This was supposed to have been an explanation for the so-called “atypical” psychoses. Attempts were made to show that such patients had inherited one psychosis from one parent and the other psychosis from the other parent. But investigation did not show this to be true. The concept of mixed psychosis has gradually-receded and in more recent times no longer plays an essential role. But the concept of “schizoaffective” psychoses has taken over and has led to attempts to distinguish these from schizophrenia and the phasic psychoses. In my own investigations the question of mixed psychoses played no important part as I was able to include most of the so-called atypical psychoses among the cycloid psychoses. For a period of time I assumed that, if different endogenous psychoses came together on a hereditary basis, one would exclude the other. But I had to correct this assumption. I can confirm that two psychoses in one person occur extremely rarely. The rarity depends, as I now assume, on the fact that different endogenous psychoses have different causes which generally are not found together in a single person at the same time. It has to be kept in mind that each separate form occurs very rarely, taking into account that the incidence of all schizophrenic disorders in the average population is less than 1%. Such rare disorders could hardly co-occur with another equally rare. I had to abandon the notion of mutual exclusion of different endogenous psychoses from the fact that such combinations may actually be observed. I did see a few in the course of many years.