Which of the following individuals demonstrates the definition of comorbidity?

a. A person who has both borderline personality disorder and a substance abuse disorder
b. A person who is histrionic who both seeks excessive attention and is emotionally hyper-reactive
c. A person with borderline personality disorder who is impulsive and tends to be in unstable relationships
d. A person who experiences a personality disorder that turns out to be fatal

Answer: A

Rationale: This is the presence of two disorders simultaneously, or the presence of a second disorder that affects the one being treated.