Children in America are undergoing electric shock treatment in growing numbers. Now known as Electro Convulsive Therapy - or ECT- the controversial treatment is being used on severely autistic children who self-harm. The BBC has been given access to film a child being treated using ECT. Our World's Chris Rogers, meets parents who say the treatment is helping their children, and the critics who say it is barbaric. Viewers may find some of the content in this film upsetting.