**Core Concept**
Delusion of doubles, also known as Capgras delusion, is a psychiatric disorder in which an individual believes that a friend, family member, or even a famous person has been replaced by an identical-looking imposter. This condition is a type of delusional disorder and is often associated with schizophrenia, bipolar disorder, or other psychotic disorders.

**Why the Correct Answer is Right**
The delusion of doubles is thought to be caused by abnormalities in the brain's neural circuits, particularly in the temporal lobe, which is responsible for processing visual and auditory information. Individuals with this condition may experience hallucinations, paranoia, and disorganized thinking, which can lead to the formation of delusional beliefs. The Capgras delusion is often accompanied by a feeling of unease, anxiety, and a sense of impending doom.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specifically relate to the Capgras delusion. While delusions can occur in various psychiatric conditions, the delusion of doubles is a distinct phenomenon that is not characteristic of all delusional disorders.

**Option B:** This option is incorrect because it refers to a different type of delusional disorder. Cotard's delusion is a condition in which an individual believes they are dead or do not exist, which is distinct from the delusion of doubles.

**Option C:** This option is incorrect because it refers to a different type of psychiatric condition. Dissociative identity disorder is a condition in which an individual experiences multiple personalities or identities, which is distinct from the delusion of doubles.

**Option D:** This option is incorrect because it does not specifically relate to the Capgras delusion. While paranoia can be a feature of various psychiatric conditions, the delusion of doubles is a distinct phenomenon that is not characteristic of all paranoid disorders.

**Clinical Pearl / High-Yield Fact**
The Capgras delusion is often associated with right hemisphere lesions, particularly in the temporal lobe, which can lead to abnormalities in visual processing and the formation of delusional beliefs. It is essential to recognize this condition as a distinct entity from other delusional disorders and to approach it with a comprehensive diagnostic evaluation.

**Correct Answer:** D.