LOR: Professor I barely know or Psychiatrist I shadowed (who knows me)?

[cogitox]

I'm applying for neuro programs this fall with concentration in the neurobiology of psych disorders. I have 2 LORs from my research lab directors, but I'm having a difficult time getting the third one. I'm a transfer student and did my BA in 2 years/did many online classes so I don't have many options. I have these two: a behavioral-neuro professor I am taking this semester -- I've met with her once to discuss graduate school and she was very nice about it, however, it is hard to develop a relationship in her class because it is so large and it has been a very short period of time (and I would need to ask her ASAP). I also know a psychiatrist (for several years) who I have shadowed in the past and I will be asking them for advice with my applications as well.

Which letter would be better to have from an admissions POV? Is it bad to have a letter from someone with whom I have a strictly professional (non-academic) relationship?

Thanks  

[sixgunguerilla]

It is not necessarily bad to have a letter from someone with whom you have a strictly professional relationship and do not listen to anyone who tells you different. This is especially true if you have strong letters from other academics, which you do. Ultimately, consider who will give you the strongest letter of the two and go with that person. If your other letters are going to demonstrate your capacity for graduate level work, there is no reason that a third letter demonstrating other strengths would not be viewed as a positive. 

[rising_star]

Go with the strongest letter.