Shortages of ADHD medications that started this summer with Adderall have widened to now include another major category of stimulants. For the past two months, patients have had a hard time finding methylphenidate drugs, a class that includes Novartis AG’s Ritalin and Johnson & Johnson’s Concerta. A drug manufacturer and a major pharmacy told Bloomberg News there are issues with the supply of the drugs, though it’s unclear what’s causing the shortage.