Dr Johnston is one of the very rare doctors in Cambridge that takes his time to really listen to you and understand what your issues are. He will not stop until he fixes the issue. He will refer you to any specialist and/or service you need to get yourself better. He is thorough and very very knowledgeable in not just traditional medicine but in natural as well. He would suggest lifestyle practices rather than medicine in cases he can. Sometimes his wait time is long... but so worth the wait!