THE METHODOLOGICAL IMPORTANCE OF DISTINGUISHING TWO SEPARATE CAUSAL CHAINS WHICH TOGETHER PRODUCE THE CLINICAL PICTURE OF PSYCHOSIS

1. Two separate and independent causal chains can explain the clinical picture in organic brain syndromes. One chain, based on pathologic-physiological changes, causes the brain function to be disturbed, and another causal chain based on psychodynamic principles determines the area of preoccupation of the patient and his particular kind of hallucinations and delusions.

2. The viewpoint is emphasized that the same distinction should be made in psychoses without known structural disturbances.

3. Pathological-physiological studies are concerned with the physical conditions which make it possible for a mental deviation to occur, and of course they are also concerned with the physical and chemical processes, correlated with thinking and feeling. The psychodynamic approach, on the other hand, uncovers the factors which determine the direction of the mental deviation or in other words why the patient has his particular kind of mental symptoms, his particular delusions and hallucinations, etc. It is obvious that both avenues of inquiry are of greatest importance; the clear understanding of the frame of reference, namely which of the two different causal chains is being investigated in a particular study may prevent misunderstanding among researchers.

4. As long as the etiology of psychoses without structural changes is unknown, the possibility exists that intense emotions may produce those physiological conditions which are necessary for the appearance of the psychosis. This possibility does not lessen, however, the practicability of the distinction of the two causal chains for clarity of thinking.