SCHIZO-AFFECTIVE disorder is an overt form of schizophrenia in which features of primary affective disturbance intermingle or alternate with fundamental symptoms of schizophrenic ego impairment. Bleuler (1911, pp. 208-211) included affective disturbances among the accessory symptoms of schizophrenia and described the occurrence in schizophrenia of both melancholic and manic conditions, the former as manifest in depressive affect and inhibition of thought and action and the latter as reflected by euphoria, flights of ideas, and hyperactivity. In regard to differentiating such a mixture of schizophrenic and affective symptomatology from manic-depressive psychosis, Bleuler (1911, p. 304) taught the following:

The presence of marked affective disturbance and an atypical course of exacerbation and recovery in apparently schizophrenic patients is reported in other early contributions by Dunton, Hoch, and Hunt and Appel. Dunton (1910) called attention to "cyclic forms of dementia praecox" characterized in part by recurring periods of "excitement" and "stupor." In his view such "cyclic" patients represented a unique form of dementia praecox that was closely allied to manic-depressive psychosis but could best be conceived as a link between schizophreniC and manic-depressive disturbance. Hoch (1922) discussed a group of patients who similarly were clearly schizophrenic and also displayed

432 Differential Diagnosis in Schizophrenia prominent affective disturbance, but he questioned whether, in light of their usual early recovery, such persons should be diagnosed dementia praecox.