**Core Concept**
Obsessive-compulsive neurosis, now classified as Obsessive-Compulsive Disorder (OCD), is a psychiatric condition characterized by recurring, intrusive thoughts (obsessions) and repetitive behaviors (compulsions) that an individual feels compelled to perform. The underlying pathophysiology involves abnormalities in brain regions, including the orbitofrontal cortex, anterior cingulate cortex, and basal ganglia, which are involved in executive function, emotion regulation, and impulse control.

**Why the Correct Answer is Right**
Research has shown that individuals with OCD have a higher risk of developing other psychiatric disorders, particularly anxiety disorders. This increased comorbidity is thought to be related to shared genetic and environmental risk factors, as well as abnormalities in brain regions involved in emotional regulation and impulse control. Specifically, individuals with OCD are at increased risk of developing panic disorder, social anxiety disorder, and major depressive disorder.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because, while individuals with OCD may experience comorbid mood disorders, the relationship between OCD and mood disorders is not as well-established as it is with anxiety disorders.
**Option B:** This option is incorrect because, although individuals with OCD may experience comorbid personality disorders, the relationship between OCD and personality disorders is not as well-established as it is with anxiety disorders.
**Option C:** This option is incorrect because, while individuals with OCD may experience comorbid eating disorders, the relationship between OCD and eating disorders is not as well-established as it is with anxiety disorders.

**Clinical Pearl / High-Yield Fact**
Individuals with OCD are at increased risk of developing other anxiety disorders, particularly panic disorder and social anxiety disorder, due to shared genetic and environmental risk factors and abnormalities in brain regions involved in emotional regulation and impulse control.

**Correct Answer: D.**