Firmly held beliefs that have a delusional quality are commonly experienced in those with schizophrenia spectrum disorders (SSD) and have been reported in those with dissociative identity disorder (DID). However, no study to date has compared delusional belief content and characteristics between these diagnostic groups. This study examined delusional content, and the degree of conviction, preoccupation and distress associated with them in 50 participants with DID and 50 with an SSD exploring also dissociation and childhood trauma as predictors of delusional beliefs. Multivariate analysis of variance and linear regressions were conducted to explore differences between beliefs and characteristics and to examine its association with dissociation and childhood trauma. The SSD sample presented more self-referential delusional beliefs and characteristics compared to the DID group. Yet, the DID group had more mistrust delusional beliefs and characteristics in comparison to SSD participants. Mistrust beliefs were predicted by depersonalization/derealization in the DID sample, but did not predict any delusional belief in the SSD sample. The content of fixed beliefs differs between DID and SSD samples and in this study depersonalization/derealization experiences were related to mistrust beliefs but not to other delusional forms, and only in the DID sample.

精神分裂症谱系障碍（SSD）的人普遍经历具有妄想质量的坚定信念，而解离性身份障碍（DID）的人也有报道。但是，迄今为止，尚无研究比较这些诊断组之间的妄想信念内容和特征。这项研究检查了50名DID参与者和50名SSD参与者的妄想内容以及与之相关的信念，专注和苦恼程度，他们还探索了解离和儿童创伤作为妄想信念的预测因素。进行了方差和线性回归的多变量分析，以探索信仰和特征之间的差异，并检验其与解离和童年创伤的关系。与DID组相比，SSD样本显示出更多的自指妄想信念和特征。但是，与SSD参与者相比，DID组具有更多的不信任妄想信念和特征。不信任信念是通过DID样本中的人格解体/去实现来预测的，但并未预测SSD样本中的任何妄想信念。固定信念的内容在DID和SSD样本之间有所不同，在本研究中，去个性化/去实现体验与不信任信念有关，但与其他妄想形式无关，仅在DID样本中。但并未预测SSD样本有任何幻想。固定信念的内容在DID和SSD样本之间有所不同，在本研究中，去个性化/去实现体验与不信任信念有关，但与其他妄想形式无关，仅在DID样本中。但没有预测SSD样本有任何妄想。固定信念的内容在DID和SSD样本之间有所不同，在本研究中，去个性化/去实现体验与不信任信念有关，但与其他妄想形式无关，仅在DID样本中。