Notes on Delusional Disorder

The term “paranoia” is derived from a Greek words meaning “madness”, “beside”, and “mind”. The term was used to describe a mental illness in which a delusional belief is the sole or most prominent feature. Kraepelin used the term “pure paranoia” to describe a condition in which a delusions was present, but without any apparent deterioration in intellect and without any of the other features of dementia praecox. The belief did not have to be persecutory to be classified as paranoia. Delusions are not rigidly fixed, but can fluctuate in intensity over time, even in the absence of treatment. Under certain conditions, delusional thinking can be modified. It has come to be realized that maintaining a strong belief against opposing evidence is not by itself abnormal but is instead a common normal human trait.