If you enjoy drinking reduced calorie pop, you might find you’re feeling a little blue.  But a morning coffee could give your mood a lift.  A BBC report says a large U.S. study has found a link between diet drinks and depression.  The research involved more than 250,000 people and found depression is more common among frequent consumers of artificially sweetened beverages.  But drinking coffee was linked with a “lower” risk of depression.  The study will be presented in March at the American Academy of Neurology’s annual meeting in San Diego.