India, Jan. 19 -- Munich (dpa) - In recent decades, around 50 countries have permitted the use of cannabis for medical reasons, following claims of its apparent effectiveness against pain, depression and inflammatory bowel conditions, despite concerns about the drug's much-discussed links to psychological disorders such as psychosis. But according to researchers led by Winfried Hauser of Germany's Technical University of Munich, the jury is still out when it comes to whether cannabis helps ease chronic nerve pain. In a paper published by the Cochrane Review, a medical journal, the team said there is little to no "high-quality evidence that cannabis-based medicines reduce neuropathic pain more than placebo across the three types of medicines...