Demand for the attention-deficit/hyperactivity disorder drug Adderall (mixed amphetamine salts) has skyrocketed in the past decade. In 2021, physicians prescribed the medication and its generic equivalents 41.4 million times. Supplies of generic Adderall XR, however, remain scarce. Amneal Pharmaceuticals, Rhodes Pharmaceuticals, Par Pharmaceutical, Sandoz and Teva had the drug on backorder in late August, according…