How do you decide when to initiate medical workup (e.g., thyroid, B12, infection) in a geriatric patient experiencing new onset or worsening low mood?

It is important to distinguish between low mood, which can occur from a host of environmental stressors, and frank depression, and there are 3 ways to look at either in the older patient:

1. Early onset depression in someone now older, and the patient feels the present one is exactly the same as previo...

I cannot think of any patient who is experiencing a mood disorder who should not also have a physical workup, including those labs.