Why do some professors have M.D. as well as/instead of a PhD?

Question

I'm interested in stem cell, regenerative medicine, developmental biology, and genetics for reverse ageing. Since these topics are dealt with in one or both of medical school and school of science and professors have one or both of MD and PhD, I'm confused about my grad school prep. Also, I'm really not interested in clinical medicine, but I want to be a researcher throughout my life.

So, I think I need only PhD, but I'm wondering why some professors in these areas have MD? Is it just because they decided to become researchers although they initially intended to work as a clinical doctor?

Answer 1

I've worked with a fair number of either researcher MDs or MD/PhDs, and myself have only a PhD, so I'll try to give my perspective:

Do You Need One: Probably not, if you're only interested in the scientific questions about what you are doing, and are not particularly concerned with it's direct application to patient care or the clinical setting. Basically, if there is a department outside a medical school that can house your research, you're likely fine.

Why Would Someone Pick One Up?: There are many reasons for a researcher to have a MD or an MD/PhD - they're interested in the clinical aspects of the research science they do, have seen their interests evolve over time toward more research and less patient care, or are in research areas that necessitate having the expertise that comes along with having an MD. There are some medical school programs that are more oriented towards producing new researchers than practicing doctors, and medical schools are massive sources of clinical research in the U.S. It's really not surprising there's a number of professors out there with MDs - my doctoral advisor was one of them.

There's also some...field-specific traditions. For example, there are tons of MDs working in infectious disease research and epidemiology, because it spawns fairly naturally from "Treat this weird infection" to "Why does this weird infection infected X people?" to "How do we stop this weird infection from spreading".

Answer 2

There are two main tracks of medicine: clinical (the "standard" medical practice), and research. Typically, doctors who work in the latter tend to pursue combined MD-PhD programs, and consequently have degrees in both a traditional scientific research discipline as well as medicine.

It probably was easier in the past to make such a switch with "just" a medical degree; however, the increased specialization in the field makes it harder for a medical doctor to switch over to a research track without the increased training (unless he or she is working on the "clinical" side of therapeutic treatments designed in research programs).

Answer 3

Regarding why one would be interested in doing an MD/PhD combo:

In my region, and I believe this generalises to the rest of Sweden, clinicians are required to do get some research experience. So for most of those MD-to-be, that's the regular entry to academia.

Furthermore, if you are a clinician with a PhD on a field related to your clinical work, your chances of promotion towards higher positions in the hospital is significantly higher, apparently.

Sadly, I do not have any references on the internet for the last statement, other than the word of my colleagues in the hospital (as well as friends who did medicine at the uni).