Delusional Disorder ICD-11 — MRCPsych Paper B MCQ

Correct answer: C — Persistent delusions predominate; characteristic schizophrenia symptoms are absent, although delusion-related perceptual disturbances may occur, and other mental functions are usually relatively preserved.

Explanation lettering: D = shown as A · C = shown as B · B = shown as C · A = shown as D

B is correct. In ICD-11 delusional disorder, persistent delusions form the predominant clinical feature. The characteristic schizophrenia pattern—such as persistent hallucinations unrelated to the delusional theme, disorganised thinking, experiences of influence or control, and negative symptoms—is not present. Perceptual disturbances may nevertheless occur when temporally and thematically related to the delusions, so stating that hallucinations are invariably absent would be too absolute. Affect, speech and behaviour are usually relatively preserved outside actions arising from the delusional system. There is no required young age of onset (A), marked global functional deterioration is not required (C), and delusions are not restricted to persecutory themes (D). Substance-induced psychosis is an alternative diagnosis rather than a requirement for delusional disorder (E).

Reference: González-Rodríguez A, Seeman MV. Differences between delusional disorder and schizophrenia: A mini narrative review. World Journal of Psychiatry. 2022;12(5):683–692. https://pubmed.ncbi.nlm.nih.gov/33370728/