Actress Amanda Bynes’ mother says her daughter’s erratic behavior (like getting a DUI, tweeting incessantly about rapper Drake, claiming she had an impostor, starting a fire, and throwing a bong out the window of her New York apartment) was all due to smoking pot. It was speculated that Bynes was suffering from schizophrenia or bipolar disorder, and she was hospitalized last spring on a 5150 (an involuntary hold for mental evaluation). “Amanda has no mental illness whatsoever,” Lynn Bynes told E! News. “[Amanda] is very sorry for all he hurtful tweets, statements, and actions that occurred while she was under the influence of marijuana." The 28-year-old Bynes recently completed treatment at Malibu’s The Canyon, and is enrolled at the Fashion Institute of Design and Merchandising in Orange County.