VIENNA — The U.N.’s drug-fighting agency says that about 200,000 people die annually from drug abuse and it would cost up to $250 billion to provide proper treatment for abusers worldwide. But the United Nations Office on Drugs and Crime says far less than that is being spent, meaning less than 1 in 5 people needing treatment actually gets help. In its annual World Drug Report published today, the agency says its 2010 estimate of $200 billion-$250 billion — about 160 billion to 200 billion euros — was equivalent to between 0.3 and 0.4 percent of the world’s GDP that year. The report says that in some countries, like the U.S., productivity losses due to drug abuse are even more costly regarding GDP.