Delusion Definition and Types A delusion is an unshakeable belief (we cannot change it with logical explanations or evidence) that is held on inadequate grounds (they do not have a valid explanation or evidence for their belief, and that is not a conventional belief that the person might be expected to hold given their educational, cultural, and religious background.   Illusions are mostly but not always normal. Hallucinations are mostly but not always abnormal. But a delusion is something that is always abnormal. So, someone who believes to be possessed by the supernatural is not delusional because it’s a cultural common belief. In the west, many young girls become convinced that they need to be thin and take extreme measures, and their weight may reach life-threatening low levels and continue. And this is still not a delusion because they consider thinness socially desirable and they educate most people about the risks of obesity is dangerous and the need for thinness. Perse...

(Mnemonic: GINPH) ● Delusions of Guilt ● Delusions of Impoverishment (can also be considered as a type of nihilistic delusion. ● Nihilistic delusions, including Cotard syndrome ● Persecutory delusions* ● Hypochondriacal delusions Patients with Psychotic depression  consider these thoughts well-deserved unlike in schizophrenia where patients feel remorse towards them and mania where patients consider them a response to the great position they have earned.  When these delusions occur against a background of depressed mood, they are mood-congruent and favor the diagnosis of psychotic depression. When patients with depression have delusions of grandeur or even neutral delusions e.g. delusions of reference, they are mood-incongruent delusions" and favor the diagnosis of schizophrenia (ICD-10).