A 19yo man has been happier and more positive than usual

A 19yo man has been happier and more positive than usual, with more energy than he has ever
felt before for no particular reason. He has been getting more work done at the office today and
has been socializing with his friends as usual. What is the most likely dx?
a. Atypical depression
b. Marked depression
c. Bipolar syndrome
d. Psychosis
e. Hypomania

Q. 1. What is the key?
Q. 2. What are the points in favour of this diagnosis?

Ans. 1. The key is E. Hypomania.
Ans. 2. i) elevated mood ii) more energy than before iii) getting more work done at the office (loss of inhibition). These features are common for both mania and hypomania!! Then why it is not mania? It is not mania as in mania you will get psychotic symptoms like i) delusion of grandeur ii) auditory hallucinations, which are absent here!