Energy drinks are both an epidemic and part of the underage drinking problem, a group of Chamber of Commerce members were told Monday."Energy drinks are being used with other things," said Hannah McDonald, Youth Program coordinator. "They're being mixed with alcohol." When stimulants, in energy drinks, and depressants, mainly alcohol, are mixed, "the body doesn't know if it's had too much to drink.""Once the stimulant wears off, you still have all that alcohol" in your system, said McDonald, of Partnership Carson City,The proliferation of "alcopops," very sweet and flavored alcoholic drinks, are fueling an epidemic of underage drinking."They're thinking about …