[Provoking endogenous psychoses]

For six forms of endogenous psychosis, causal agencies were sought to establish endogenous, physical, and mental provocation. Endocrine causes were found most frequently, 17.5%, in mixed bipolar disorders, followed by cycloid psychoses, 8.5%, which in this respect appear to be closer to the mixed bipolar psychoses, than the unipolar forms at 4.4%. Among the physical causes, the difference in affective psychoses is not particularly great. Cycloid psychoses head the list at 9%. Among the mental causes, pure phase psychoses account for the greatest number, 12.7%, by a wide margin. The three unsystematic forms of schizophrenia revealed a slender link with their causes. Clear distinctions among the causes of the six forms were thus demonstrated.