This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET Jan 2020, Subject name: Psychiatry
A 1styr medical student presents with recurrent episodes aof choking sensation, breathlessness, intense sweating along with feeling of impending doom. Usually the episodes occur prior to exams. What is the most likely diagnosis? 
Select and explain. 
A. Panic attack, B. Acute stress disorder, C. Generalised anxiety disorder, D. Phobia
A: Panic attack
Answer: A: Panic attack 
Explanation: Panic attack:An acute attack of intense anxiety, witha 'feeling of impending doom' Patient present with Palpitations, choking sensations, chest pain, dizziness, depersonalization , derealization Fear of having a hea attack, dying or going mad Panic disorder:Recurrent and unexpected panic attacks Serotonin, norepinephrine and GABA are the major neurotransmitters involved in panic attacks. Cholecystokinin and pentagastrin (which acts on CCK receptors) are also known to cause panic attacks.