This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
A 40 year old man is showing symptoms of mania since few days. What is the minimum time duration for the diagnosis for mania? 
Select and explain. 
A. 1 week, B. 2 week, C. 3 week, D. 4 week
A: 1 week
Answer: A: 1 week 
Explanation: A distinct period of abnormally and persistently elevated, expansive, or irritable mood, lasting at least 1 week (or any duration if hospitalization is necessary). Ref: Harrison's Online > Pa 17. Neurologic Disorders > Section 5. Psychiatric Disorders > Chapter 391. Mental Disorders > Mood Disorders > Bipolar Disorder > Clinical Manifestations > Table 391-10.