There is so much Research supporting Medical Marijuana that it is very hard to know where to start. To put it as plainly as possible, there is not one major medical association that has taken a position against medical use of cannabis, where as there are many (listed here) that have released statements in favor of medical marijuana. Medical associations take into account research and the care of their patients when they make the decision to add their organization's name to the list.
Americans for Safe Access has done a great job outlining research on medical marijuana.
On this site you will find clinical studies with cannabis or single cannabinoids in different diseases and case reports on the use of cannabis by patients.
You may search for diseases (indications), authors, medication, study design (controlled study, open trial, case report, etc.) and other criteria. Clinical Studies and Case Studies
The Beckley Foundation online library comprises an extensive scientific bibliography, with research papers on the many subjects in which the Foundation is involved.
It provides many thousands of the citations, many with full text versions of these papers. The psychedelic library covers papers from the very earliest period of research right up to the most recent studies. The database was developed by the Beckley Foundation with the collaboration of scientists and organizations, such as the Heffter Institute, the Albert Hofmann Foundation, Erowid, MAPS, and the ProMind Foundation.