A 65 year old woman says she died 3 months ago and is very distressed that nobody has buried her. When she is outdoors, she hears people say that she is evil and needs to be punished. What is the most likely explanation for her symptoms?

The key is C. Psychotic depression. [Psychotic depression, also known as depressive psychosis, is a major depressive episode that is accompanied by psychotic symptoms (hallucinations, delusions). In this patient nihilistic delusion favours the diagnosis of psychotic depression. It can occur in the context of bipolar disorder or majordepressive disorder].