**Core Concept**
Erotomania is a psychiatric disorder characterized by a delusional belief that another person, often of higher social status or a celebrity, is in love with the individual suffering from the condition. This delusional belief is typically accompanied by feelings of elation and grandiosity.

**Why the Correct Answer is Right**
The pathophysiology of erotomania is not fully understood, but it is believed to be related to abnormalities in neurotransmitter systems, particularly dopamine and serotonin. Individuals with erotomania may exhibit symptoms of obsessive-compulsive disorder, such as repetitive thoughts and behaviors, as well as symptoms of anxiety and depression. The delusional nature of the disorder is thought to be a result of a misfiring of the brain's reality-testing mechanisms.

**Why Each Wrong Option is Incorrect**
**Option A:** Delusional disorder is a broader category of psychiatric disorders that includes erotomania, but it is not a synonym for erotomania.
**Option B:** Othello syndrome is a delusional disorder characterized by a belief that one's partner is unfaithful, which is distinct from erotomania.
**Option C:** De Clerambault's syndrome is another term for erotomania, named after the French psychiatrist who first described the condition.

**Clinical Pearl / High-Yield Fact**
Erotomania is also known as De Clerambault's syndrome, named after the French psychiatrist who first described the condition in the 19th century. It is essential to distinguish erotomania from other delusional disorders, such as Othello syndrome, which is characterized by a belief that one's partner is unfaithful.

**Correct Answer: C. De Clerambault's syndrome**