A CANADIAN woman was denied entry to the United States last month because she had been hospitalized for depression in 2012. Ellen Richardson could not visit, she was told, unless she obtained “medical clearance” from one of three Toronto doctors approved by the Department of Homeland Security. Endorsement by her own psychiatrist, which she could presumably have obtained more efficiently, “would not suffice.” She had been en route to New York, where she had intended to board a cruise to the Caribbean.