Arizona Republic:  “A new University of Arizona study shows little or no evidence that medical marijuana is an effective treatment for anxiety, migraines, depression and post-traumatic stress disorder, a finding that could hinder efforts to expand the allowable uses for the drug in Arizona.  The researchers, working on behalf of the state Department of Health Services, which oversees the state’s medical-marijuana program, reviewed dozens of scientific studies related to marijuana use for the four medical conditions and determined that most of the research was of little value in weighing the medicinal risks and benefits.”