As stated, the answer is no. But "academic medicine" is complex and has many faces. As far as getting a PhD, it depends on how you want to work and what type of research you want to do. In academia, most MD/PhD's tend to have the role of PhD's, but are valued highly as researchers because they also have the rare MD behind their name. It's the most prestigeous degree for a medical researcher. So, do you want to do what you see your current professors doing, teaching lectures, with a basic science research lab, in addition to the occasional clinical experience? In other words, be a researcher who also sees patients every now and again...once a week, or a couple times a month? That'd be the indicator to go the PhD route. You can go a more clinically oriented route as an MD/PhD, and you are not limited in any way once you have the PhD if you decide to basically work as an MD, but the PhD becomes fairly unnecessary and will not increase your pay.
Research is also abundant in academic medicine amongst MD-only's, but your research is generally oriented towards advancing clinical practices, not so much the basic science "discovery" type stuff. Most do not run labs and those involved in basic science work as the clinical component of a project that involves PhD's. (Although again, there are exceptions. One of the chairs of a surgery department at my school runs a well known basic science lab. Oncology and med genetics are two other fields where clinicians can do a lot of basic science research). Certain specialties are particularly heavy on clinical research and value it highly, but it's important across the board in academics. In particular, most competitive specialties nowadays more-or-less require research experience during med school in order to match. Ortho, ENT, plastics, and neurosurgery fall into this category. Same with derm, ophtho and uro to some extent, and definitely cardiology as well (although lots of cards research is generally done during IM residency). As a doctor in these fields, if you work at an academic institution, you'd have the opportunity and usually the requirement to continue doing research. They are publishing articles, but don't generally run labs, write grants, or give lectures to students.
Oh, also, the payscale varies significantly depending on the role you choose (not so much the degree itself). MD/PhD's who are primarily researchers are paid at the level of PhD's, whereas those in clinical practice that have to do research as part of their practice, are on the MD scale. For example, my MD/PhD pathology professor makes $100K and does not practice, whereas the cardiologist giving my current pathology lectures on the heart, who works primarily as a practicing cardiologist, makes $400K. There are exceptions to this too, as I know two PhD's at my school that make close to $500K, but they are absolutely leaders who have revolutionized/created their field, and it's not something anyone should expect. That's why they finance the MSTP route for you, and why you should only do it if you're really passionate about basic science research.
Hope that helps.
