In addition to conventional, intensive Applied Behavioral Analysis (ABA) therapy, McCarthy prescribed for her son a gluten-free and casein-free diet, hyperbaric oxygen chambers, chelation, aromatherapies, electromagnetics, spoons rubbed on his body, multivitamin therapy, B-12 shots, and numerous prescription drugs. "Try everything", she advises parents. "It was amazing to watch, over the course of doing this, how certain therapies work for certain kids and they completely don't work for others. ... When something didn't work for Evan, I didn't stop. I stopped that treatment, but I didn't stop." McCarthy has stated on talk shows and at rallies that chelation therapy helped her son recover from autism. The underlying rationale for chelation, the speculation that mercury in vaccines causes autism, has been roundly rejected by scientific studies, with the National Institute of Mental Health concluding that children with autism are unlikely to receive any benefit to balance the risks of heart attack, stroke and cardiac arrest posed by the chelating agents used in the treatment.