Here are definitions that correspond to each of the options you provided related to mental illness:
a. Comorbidity - Two conditions that affect health at the same time.
b. Bipolar Disorder - A mood disorder characterized by extreme highs (mania or hypomania) and lows (depression).
c. Panic Attack - Episodes of intense fear that can trigger severe physical reactions in the absence of real danger.
d. Mental Health Disorder or Clinical Disorder - A health condition in which negative or unhelpful feelings or thoughts become so severe they interfere with daily life.
If you need more information or further clarification on any of these terms, feel free to ask!