ABSTRACT
This chapter provides a case of a 79-year-old man with unpredictable behaviour. He has started to become more and more suspicious of all his family members, particularly his wife. He thinks she is poisoning him and will now no longer eat anything she has cooked. He does not even trust her to make him a drink. He admits he has had some auditory hallucinations which are somewhat unclear. He is also convinced that he could look after himself without any help from his family. He has not had any self-harm ideation or plans. Paranoia can occur in many contexts. It may be part of a personality disorder with a long-standing mistrust about other people. If it is delusional in intensity it may be part of a psychotic disorder such as persistent delusional disorder or schizophrenia or part of a manic-depressive or depressive psychosis. It could be part of a transient or drug-induced psychotic disorder.
