Relevant dimensions of delusions: continuing the continuum versus category debate

Delusions and hallucinations are common among healthy individuals but may differ from the symptoms experienced by persons with schizophrenia. It is hypothesized that specific dimensions of delusions, such as the distress associated with them, preoccupation, conviction or their content might be more relevant in distinguishing persons with from persons without schizophrenia than the mere presence of delusional beliefs. Second, it is investigated whether delusional beliefs are as closely linked to hallucinations in a non-clinical population as in persons with schizophrenia. The Peters et al. Delusions Inventory and the Launay Slade Hallucination Scale - Revised were used to assess delusional ideation and hallucinatory experiences in a population sample that reflects the general population in age, education and gender (n=359) and in persons diagnosed with life-time schizophrenia in varying stages of remission (n=53). There was a strong association of delusional ideation and hallucinatory experiences in both groups. Stepwise discriminant function revealed the distress associated with delusions as well as beliefs involving persecution and loss of control to be the most relevant aspects in distinguishing persons with from persons without schizophrenia. It is concluded that delusions should be assessed multi-dimensionally, laying particular emphasis on distress and content of beliefs.