Comparison of schizophrenic delusions between Japan and Germany

The content of schizophrenic delusions of 150 German patients in the Psychiatrische Universitätsklinik Tübingen and those of 324 Japanese patients (ICD-9:295) were compared according to the classification of Huber and Gross. The comparison revealed significantly higher frequencies of delusions of poisoning (18 vs. 8%; p < 0.01) and jealousy (6 vs. 1.9%; p < 0.05) in the German cases, but there was no significant difference in the incidence of comprehensive injury delusions. There was also no significant difference in the incidence of comprehensive grandeur delusions. However, comprehensive belittlement delusions were more frequent in the German group (24 vs. 13.3%; p < 0.01). Among the delusions of this type, the themes of guilt/sin (15.3 vs. 4.9%; p < 0.001), particularly those related to religion, were more frequent in the German group. Although religious delusions were more frequent in the German group (21.3 vs. 6.8%; p < 0.001), the difference regarding the incidence of 'delusions of world destruction' was not statistically significant. Among the persecution/injury delusions, themes of direct persecution from others (Verfolgungswahn) were conspicuous in the German group, whereas delusions of reference (Beziehungswahn) related to harassment, such as 'being slandered by others' or 'being known', were common in the Japanese group. Namely, the difference in the content of these persecution/injury delusions may derive from the different types of self in the two countries: the individually oriented self in Germany and the group-oriented self in Japan. Delusions of guilt/sin in the German group may reflect the characteristics of sin in Christianity.