Potheads rejoice! Turns out cannabis use was not associated with an increased risk for developing mood or anxiety disorders after all. With more states legalizing marijuana for medical and recreational use there are renewed clinical and policy concerns about the mental health effects of the drug. In a new study Columbia University's Mark Olfson and coauthors examined marijuana use and the risk of mental health and substance use disorders in the general population. The study used a nationally representative sample of 34653 U.S. adults interviewed three years apart in the National Epidemiologic Survey on Alcohol and Related Conditions. (Read: Is
